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"Us" and "them": disagreement over the meanings of terms, ambiguity, contestability and strategy in the Zimbabwean House of Assembly

- Hasler, Arthur Richard Patrick

Authors: Hasler, Arthur Richard Patrick
Date: 1989
Subjects: Politicians -- Zimbabwe -- Language , Zimbabwe -- Politics and government -- 1980- |xLanguage
Language: English
Type: text , Thesis , Masters , MA
Identifier: vital:2083 , http://hdl.handle.net/10962/d1001600
Description: This is a study of how certain value loaded political terms are used in Zimbabwean Parliamentary debate. Before 1980 it is argued that aspects of lexical choice and an individual's sociopolitical position were extremely closely related, especially in the case of "white Rhodesians". There was also a marked lack of ambiguity in the use of value loaded terms at this time. In contemporary Zimbabwean House of Assembly, however, terms which became popularized when the new government came to power in 1980 are used with considerable ambiguity and contestability in order to further specific strategies. Though correlations between the choice of lexical units and individuals' positions in the social structure have been identified as "sociolinguistic variables" (Downes 1984, 75), it is argued that an analysis of this type of correlation should lead us to an analysis of how these lexical units or "terms" are used by individual speakers in a micro-political process. I hypothesize that the ambiguity and contestability which encompass certain key terms used in the Zimbabwean House contribute to their being used as strategies to achieve individual or party goals. I show that the terms are manipulated by individuals in various contexts, and that the normative connotations of terms, that is what the terms "ought" to mean, is not consistent with the ways in which they are used. This, in turn, has an effect on how people think the terms should be used. This process of language change exposes the interface between language usage and social life. Though not reducible to a single "correct" interpretation, it does provide rich material for the analysis of culture.
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Date Issued: 1989

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A case study of narcissistic pathology : an object relations perspective

- Ivey, Gavin William

Authors: Ivey, Gavin William
Date: 1989
Subjects: Narcissism Narcissism -- Treatment
Language: English
Type: Thesis , Masters , MSocSc
Identifier: vital:3188 , http://hdl.handle.net/10962/d1008453
Description: The case-study method of psychological research was applied to the brief psychodynamic therapy of a narcissistically disordered female patient. The aim of this research was to explore, clarify and explain certain diagnostic and psychodynamic anomalies to emerge in the course of treatment, using a conceptual framework derived from select psychoanalytic object relations theorists in the area of narcissistic pathology. The author, discovering that there was no diagnostic or explanatory object relations model adequate to the therapeutic data, formulated his own diagnostic category narcissistic neurosis and an eclectic object relations model in order to explain the anomolous research findings. Narcissistic neurosis was defined as a form of psychopathology in which a primarily neurotic character structure presents with a distinctly narcissistic profile. The narcissistic false self-structure serves the functional purpose of protecting the psyche from a repressed negative self-representation derived from a destructive bipolar self-object introject. The primary etiological factor to emerge was that of a narcissistic mother conditional affection and self-object target child necessitated adaptive whose insensitivity, relationship with the premature self-sufficiency and the defensive emergence of a narcissistic surface self-representation. It was proposed that narcissistic neurosis and narcissistic personality disorder are two discrete forms of pathology differing in terms of severity, psychodynamics, defensive structure, mode of object relating, therapeutic accessibility and prognosis. Assessment criteria were proposed in order to differentiate the two areas of narcissistic pathology and assess suitability for psychotherapeutic treatment. Positive treatment results in this case-study suggest that narcissistic neuroses may receive long-term benefit from short-term psychodynamic therapy.
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Date Issued: 1989

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A critical evaluation of the human skin blanching assay and comparative bioavailability studies on topical corticosteroid preparations

- Meyer, Eric

Authors: Meyer, Eric
Date: 1989
Subjects: Dermatopharmacology Skin, Effect of drugs on Adrenocortical hormones
Language: English
Type: Thesis , Doctoral , PhD
Identifier: vital:3727 , http://hdl.handle.net/10962/d1001464
Description: Several aspects of the human skin blanching assay were evaluated in an attempt to suggest improvements in the methodology of this assay. Three trials were performed in the unoccluded application mode, using two proprietary creams containing 0,1% betamethasone (as the 17-valerate). Preliminary observations of the influence of ambient temperature and relative humidity on the blanching response did not allow definite conclusions to be drawn. Studies on the number of observers required for reliable results of comparative blanching indicated that at least two trained observers should be employed. Analyses of the results of individual volunteers demonstrated the expected biological variability, and suggest that subjects selected for trials should represent a range of blanching responses. No sex-related differences in blanching responses were found, and both arms exhibited similar sensitivity to corticosteroids. Retrospective analysis of 95 040 observations of blanching responses showed that in the unoccluded application mode blanching is lowest close to the wrist, and in the occluded mode blanching is lowest close to the elbow. Studies on the method of transportation of Betnovate preparations suggest that topical formulations should not be exposed to temperature extremes during transportation. It is proposed that patients should not transport topical formulations in the holds of ships or aircraft, and that exporters and manufacturers should make use of special transportation and storage conditions. In a study of ten topical formulations from three countries it was found that there was no trend of products from one country consistently exhibiting superior blanching to products from the other two countries, or products from one country consistently exhibiting the lowest degree of blanching, although considerable differences in blanching responses were found in some cases. Interpretation of the results of these studies demonstrated the importance of employing a combination of statistical analyses, blanching profiles and AUC values when drawing conclusions regarding comparative bioavailability. A study of the blanching profiles of Betnovate cream included in all 16 trials performed during this work indicated that this preparation behaved in a similar fashion during all trials, thereby giving credence to the results of the trials
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Date Issued: 1989

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A history of the Qwathi people from earliest times to 1910

- Ndima, Mlungisi

Authors: Ndima, Mlungisi
Date: 1989
Subjects: Qaba (African people) -- History
Language: English
Type: Thesis , Masters , MA
Identifier: vital:2550 , http://hdl.handle.net/10962/d1002402 , Qaba (African people) -- History
Description: This is the first history of the Qwathi to appear. It relates all the events which have shaped the historical consciousness of the Qwathi people. The first chapter deals with the foundation of the Qwathi chiefdom by Mtshutshumbe and his followers who emigrated from EmaXesibeni to Thembuland before 1700. It also covers the development of the various Qwathi clans. The reign of Fubu which is discussed in Chapter Two was characterised by warfare. The most important of these wars was the Qwathi-Thembu war of the beginning of the nineteenth century. Its importance lies in the fact that although the Qwathi were a small chiefdom, they were able to goad the Thembu nation into war, the results of which were indecisive, hence, in subsequent years, the Thembu were always cautious in their dealings with the Qwathi. Fubu's other wars, including those of the Mfecane, are also discussed. Chapter Three deals mainly with the Qwathi-Thembu relations during the reign of Dalasile, Fubu's son. These were at first cordial but they became strained when Ngangelizwe took over as Thembu king in 1863. Dalasile refused to involve the Qwathi people in Thembu conflicts with their enemies and he desired to pursue an independent line. In 1875, when Ngangelizwe accepted colonial control, Dalasile stood out against it but, under pressure from the agents of colonialism, he gave in. The period from 1875 to 1880 was one of passive resistence to colonial control. This erupted into Dalasile's rebellion against the colony from 1880 to 1881. Chapter Six deals with the surrender, relocation and the introduction of a new system of control called the "Ward System". The ruling house was replaced by appointed headmen most of whom were drawn from non-Qwathi communities. Chapter Seven deals with the rise and Fall of the Qwathi peasantry. The fall of the peasantry facilitated labour migracy which contributed to further deterioration of the Qwathi both economically and physically.
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Date Issued: 1989

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A history of the Thembu and their relationship with the Cape, 1850-1900

- Wagenaar, E J C

Authors: Wagenaar, E J C
Date: 1989
Subjects: Tembu (African people) -- History Missions -- South Africa -- Cape of Good Hope South Africa -- History -- Frontier Wars, 1811-1878 Cape of Good Hope (South Africa) -- Politics and government Land tenure -- South Africa -- Cape of Good Hope
Language: English
Type: Thesis , Doctoral , PhD
Identifier: vital:2569 , http://hdl.handle.net/10962/d1002422
Description: Present day Thembuland is situated roughly between the Mthatha and Kei rivers. It lies within the south-western portion of the political unit which has been known since 1976 as the Republic of Transkei. It comprises the territories formerly known as Emigrant Thembuland (now the districts of Cala and Cofimvaba) and Thembuland Proper, i.e. the districts of Mqanduli, Umtata, Engcobo and Bomvanaland. We have evidence that Thembu people had already settled in Thembu land Proper, at the Mbashe river, by the beginning of the 17th century. Pioneering clans many have entered the territory at a much earlier date. In the 1830's some clans broke away from the Mbashe settlement, and moved to the region of present day Queenstown. In 1853 their lands were included in the so-called Tambookie Location, which in 1871 became the district of Glen Grey. Emigrant Thembuland came into existence in 1865 when four chiefs from Glen Grey accepted Sir Philip Wodehouse's offer to settle on the lands across the White Kei whence the Xhosa chief Sarhili had been expelled in 1857. This thesis deals with the history of the people who lived in these territories between 1850 and 1900.
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Date Issued: 1989

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A hydrogeological investigation of the Grootegeluk mine

- Johnstone, Andrew Clifford

Authors: Johnstone, Andrew Clifford
Date: 1989
Subjects: Hydrogeology -- South Africa Coal mines and mining -- South Africa
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:4795 , http://hdl.handle.net/10962/d1001895
Description: The study concerns an assessment of the hydrogeological impact of an open cast coal mine in the North Western Transvaal Province of South Africa. The hydrogeological impact of the mine is assessed in terms of groundwater quality and levels. A monitoring system was installed to enable the present and future impact of mining operations on the hydrogeological regime to be assessed. Grootegeluk Mine is situated in the Waterberg Coal Field of South Africa and began production in 1980. The mine extracts fifteen million tons of mine material annually from a single open pit. Forty percent of the mined material is saleable product and the remaining sixty percent is stacked on discard dumps. The Daarby fault forms the northern boundary of the open pit and serves to bring the younger Letaba and Clarens Formations into contact with the older Beaufort and Ecca Groups. The mine discards are deposited north of the fault on a different hydrogeological environment from which they are mined. Dewatering of the mine open pit has resulted in a steady decline in water levels in the Ecca Group, south of the Daarby fault. In contrast, water levels north of the Daarby fault in the Letaba and Clarens Formations have risen. The short term hydrochemical impact of the mine discard dumps and slimes dams have resulted in a rise in the calcium, sulphate, chloride, fluoride and nitrate concentrations of the ambient groundwater . The longer term hydrochemical impact from the waste dumps, acid mine drainage, is not evident at present in the groundwater below the waste dumps. However, it is expected to manifest itself during the next ten years. A monitoring system was installed at the mine to allow groundwater levels and quality to be monitored. By measuring groundwater quality and levels the impact of the mine on the regional hydrogeology can be monitored and assessed presently, and during the next forty years of production. Monitoring will also enable the timeous implementation of remedial measures at an early stage and eliminate the need for large late stage "clean up" operations. Future monitoring of both water levels and quality will be crucial in evaluating the mine's impact on the regional groundwater regimes over the next forty years of production. The remedial measures recommended for leachate presently emanating from the waste dumps and slimes dams north of the Daarby fault, are a number of collector wells drilled into the basalts and sandstone north of the Daarby fault. The proposed positions of the wells (boreholes) are as close as possible to the dumps and slimes dams with expansion taken into consideration. The boreholes should be designed to lower the water level in the vicinity of the dumps in order to create a nett groundwater gradient towards the dumps and as a result, halt the spread of leachate away from the dumps. Grootegeluk plans to backfill the open pit with plant discards on completion of the mining of zone 2. The backfilled material will consist of the currently produced plant waste and will be covered with overburden and topsoil. It is expected that the backfilling will have a major impact on groundwater quantity if no remedial measures are implemented. The two remedial measures discussed are chemical treatment of the discard material before backfilling or the continual abstraction of water from the pit resulting in a nett groundwater inflow into the pit. No material from the present waste dumps and slimes dams will be transported into the open pit as backfill material
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Date Issued: 1989

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A metabletic study of the male/female process in psychology

- O'Brien, Keith Stanley Edward Michael

Authors: O'Brien, Keith Stanley Edward Michael
Date: 1989
Subjects: Psychology -- Philosophy , Sex difference (Psychology) , Psychotherapy
Language: English
Type: text , Thesis , Masters , MA
Identifier: vital:2908 , http://hdl.handle.net/10962/d1002073
Description: The motivation to explore the subject matter of this thesis arises from two interlinked processes: (1) the experience of the power and pervasiveness of a "basic split" experienced in therapy in the unity of the individual, (2) the tendency in the unitary discipline psychology for theorists to adopt views which are polar opposites. In trying to understand these phenomena one has to explore the basic paradox of being which has fascinated thinkers and mystics down through the ages, the paradox of the One and the many, and thus the phenomenon of change. This paradox is explored in mythology, in the "philosophia perennis" and as encountered in high-energy sub-atomic physics. Out of this emerges the awareness of Being as One but as embodying a dynamic polar process, the first of whose manifestations is the male and the female process (or Yin/Yang in Chinese). The male/female process is defined and explored and it is shown that the female process has been progressively ignored and largely repressed in the West. I demonstrate this process in a metabletic (hermeneutical phenomenological) study of Greek sacred architecture. Metabletics as defined by its originator, J.H. van den Berg, is "the theory of change" or a psychology of history. It is thus a particularly suitable method of analysing the cultural-historical process of the repression of the female process in Western society. The emergence of the male process as predominant in the West is explored hermeneutically through the emergence of the individual and the suppression of the old unity centred in the Mother Goddess, and the receding of the Father God to the heavens. The choice by the great Greek philosophers of the male process is particularly important because of their emphasis on the Logico-Mathematical Sequential (L.M.S.) mode of knowing and perception at the expense of the female process, Intuitive-Creative Holistic (I.C.H.) mode.The dominance of the male process in the West is traced from the aboriginal female-process state through neolithic village culture to the rise of the first cities. Processes studied are the rise of kingship, war, private property and the splitting of labour. The roots of anomie and alienation are described. The emergence of god as powerful ruler and lawgiver is shown. The splitting of the male/female process leads to the splitting of the individual from him/herself, from others, from the world and from the divine. This is traced in the mystery religions, in religious dualism, in the rise of the Judaeo-Christian tradition and Gnosticism. The split and its effects are demonstrated in Western science and psychology. The necessity and possibility of integration in science and in psychology is demonstrated through the integration of our process of knowing and perceiving which is used as a model for the integration of psychology. The effects of the male/female split on the individual in Western society are shown. The split in our society leads to anomie and alienation, which produce "socioses". These affect the child born into the society and lead to a "Parent/Child" split. The possibility of healing the split in the individual, between people, between humankind and the world and in re-establishing our unity in the One is illustrated. The unity of the One is experienced through the dynamic polar interaction of the male/female process.
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Date Issued: 1989

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A mission and five commissions: a study of some aspects of the educational work of the American Zulu Mission, 1835-1910

- George, Ambrose Cato

Authors: George, Ambrose Cato
Date: 1989
Subjects: Missions -- South Africa Missions -- Educational Work , American Zulu Mission , Natal , South Africa , Colonial government , Adams College , Newton Adams , Missions , Missionary education , Educational purpose , Zulu people
Language: English
Type: Thesis , Doctoral , PhD
Identifier: vital:1337 , http://hdl.handle.net/10962/d1001403
Description: This thesis examines the work of the American Zulu Mission in Natal from 1835 to 1910. Of the institutions controlled by this mission, the most famous was that known in the 20th Century as Adams College, named after one of the founders of the Natal work, Dr Newton Adams. Although other research work has been done on this institution and this mission in general, this thesis attempts to examine the work in the light of the mission's own view of its educational purpose and the expectations of the Colonial Government of what could be expected of missionary education. To meet this purpose particular stress was laid first on the actual development of the mission's educational institutions, especially when reports and letters assessed the aims of the developments and the ways in which these aims were being met. Secondly, the aims of missionary education were explained through five capital Colonial Government Commissions, which looked, in a number of different ways, at the current position and future of the Zulu peoples of Natal. These Commissions reported in 1846, 1852-1853, 1881-1882, 1892 and 1902. Two major findings emerge from the investigation. The first was lack of clarity, not only on the part of what the mission was trying to do, but also on what the Colonial Government expected it to do. To this absence of clarity must be added the continuous shortage of finance, the reluctance of the Zulu themselves to accept the combination of education (which they wanted) and conversion (of which they were often suspicious). In these circumstances, their slow progress of the 75 years from 1835 to 1910 becomes understandable. Had these years been the total extent of the mission' s contribution to Natal, there would be little justification for any extended investigation, or any reason behind the high prestige which the mission enjoyed. It is shown, however, that from 1902 onwards a new, more incisive and directional policy, especially on the question of education, came from the mission. This emerged particularly under the leadership of Le Roy, Principal from 1903 to 1925. The last part of this thesis assesses this new direction. The detailed investigation comes to an end at 1910 when with the creation of Union, an entirely new organisation and dispensation came into being. In the last years of Le Roy's principalship the promise of the period of 1902 to 1920 came to fruition and in the final chapter a brief summary of these developments are given
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Date Issued: 1989

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A phenomenological investigation into the psychotherapist's experience of identifying, containing and processing the patient's projective identifications

- Thorpe, Mark Richard

Authors: Thorpe, Mark Richard
Date: 1989
Subjects: Psychotherapist and patient Psychotherapy Methods
Language: English
Type: Thesis , Doctoral , PhD
Identifier: vital:3071 , http://hdl.handle.net/10962/d1002580
Description: The aim of the study was to describe the therapist's lived experience of identifying, containing and processing the feelings, thoughts or fantasies evoked in him by the patient's projective identifications. A question which would elicit the experience of this phenomenon was formulated by examining case histories, and modified through the use of individual pilot studies. Fifteen experienced, psychoanalytically oriented psychotherapists were interviewed. The eight psychologically richest accounts were chosen for the study. Using the empirical phenomenological method, the four protocols that most clearly reflected the phenomenon were analysed in detail, while the remaining four were used to clarify areas of uncertainty. Projective identification is conceptualised as the process whereby the patient coerces the therapist to embody an un-appropriated aspect of his (patient's) world. The context of processing a patient's projective identification was discovered to be such that the therapist finds himself coerced to embody an incongruent, unfamiliar, confusing and inauthentic state of being which is consonant with the patient's perception of him. The discomfort of the experience leads the therapist to bring to awareness and thematise his feeling-state. He alternates between avoiding this state of being, which results in conf1ict with the patient and the therapist's own values, and appropriating it, which feels inauthentic. The therapist moves from a position of trying to understand the experience in relation to his own world, to the realisation that it is co-determined by the patient. From a position of reflective distance he re-appropriates aspects of his world that were closed to him while under the influence of the patient, in addition to appropriating previously unowned aspects. The therapist dialogues these appropriations with the invoked feelings, allowing him to differentiate those aspects of his feeling-state which are authentically his from those which are unowned aspects of the patient's aspects of his world that were closed to him while under the influence of the patient, in addition to appropriating previously unowned aspects. The therapist dialogues these appropriations with the invoked feelings, allowing him to differentiate those aspects of his feeling-state which are authentically his from those which are unowned aspects of the patient's world that he has been forced to embody. Through this process the therapist clarifies and gives meaning to his feelings. The therapist fee1s re1ieved and lighter, when in the service of the therapy, he temporarily gives himself over to the patient's experience of him, without feeling drawn to either disowning or appropriating it, while simultaneously remaining open to his own authentic reality. These findings were dialogued with the literature on projective identification.
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Date Issued: 1989

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A political history of the Bhacas from earliest times to 1910

- Makaula, Anderson Mhlauli

Authors: Makaula, Anderson Mhlauli
Date: 1989
Subjects: Bhaca (African people) , South Africa -- History
Language: English
Type: Thesis , Masters , MA
Identifier: vital:2548 , http://hdl.handle.net/10962/d1002400 , Bhaca (African people) , South Africa -- History
Description: The Bhacas are people whose history has not yet been clearly written. Unlike the Mpondo, Xhosa and Thempu chiefdoms, the Bhacas are comparatively recent immigrants into the Cape area. The first chapter deals with origins of the Bhacas and introduces the reader to Bhaca affairs. The chiefdom is said to have been a victim of the disruptive Tshakan wars of the early 19th century, and Madzikane, who later on assumed the reputation of being the architect of the Bhaca nation, left Natal seeking a place where to establish his independence. He collected a large number of fugitives scattered in the southern part of Natal and migrated to the Embondzeni Great Place in Mount Frere. The second chapter concentrates on the habits and customs of the Bhacas. The Bhacas of Mount Frere district are divided into two autonomous chiefdoms according to the descendants of Sonyangwe and Ncapayi, sons of the renowned Great Bhaca chief, Madzikane. Bhaca customs are characterised by their First Fruit Festival dialect.(ingcubhe) and their distinctive Thsefula Then comes the era of Ncapayi who had been renowned for his warlike propensities, and the controversial Voortrekker attack of 1840. It was however, during his reign that mission work started amongst the Bhacas. This left an indelible impression among the Bhacas because Osborn Mission Station was established in 1858 during Mamjucu's reign, the widow of Ncapayi, many years after his death . The influence of missionaries coupled with the problems encountered by Makaula, Ncapayi's son from the surrounding chiefdoms, led to the acceptance of colonial rule. This leads us to chapters 6, 7 and 8 where the colonial government interfers in the Bhaca traditional administrative system especially in matters relating to the allocation of land, appointment of headmen, relations between Makaula and Nomtsheketshe and relations between the Bhacas and the Mpondo. It was during Makaula's regime that many denominations were established in the Mount Frere district. A great measure of credit should be given to these churches for placing systematically before the Bhacas the higher standards of belief and conduct. The history of Bhacas from the 1860's was characterised by change and modification due to the increasing contact with the white man's culture.
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Date Issued: 1989

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A portrait of a school : Healdtown Missionary Institution (1925-1955) through the eyes of some of its ex-pupils

- Peppeta, Joseph Ability Mzwanele

Authors: Peppeta, Joseph Ability Mzwanele
Date: 1989
Subjects: Healdtown Institution , Black people -- Education -- South Africa -- History
Language: English
Type: Thesis , Masters , MEd
Identifier: vital:1339 , http://hdl.handle.net/10962/d1001405
Description: The study is on Healdtown Missionary Institution. A broad background has been given from 1855 when the Institution was established by Sir George Grey. The emphasis has, however, been from 1925 when the earliest respondents were admitted, up to 1955 when the Department of Bantu Education took over from the missionaries. This period has been deliberately chosen since Healdtown was largely run by the Wesleyan Missionaries during that time. It must also be mentioned that the administration side of Healdtown has not been covered, since Professor Hewson has given a broad picture of this aspect in his doctoral thesis (1959). Similarly, the situation in the classrooms has not been considered except where appropriate references have been cited by respondents. The stress is on the different activities that took place, mainly in every day life in the Institution. Some of these are the positions of responsibility held by respondents in the Institution and their effect on them (the respondents) in later life. This can be coupled with the contribution the respondents made to their communities after leaving Healdtown. The most important thing about the study is what has been revealed with regard to the three generations: the parents of the respondents, the respondents themselves and the children of the respondents. In this aspect a picture of how elite produces elite has been highlighted. To add more flavour, the memories, both good and bad, have been analysed and in order to see whether these are common or peculiar, a comparison was made with similar day schools (secondary) in Soweto. In the conclusion, especially, the limited opportunities for Black pupils to have secondary education during this period is also highlighted. This goes with the eagerness and efforts shown by parents to give secondary schooling to their children. Last, but not least, in the conclusion to this thesis certain deductions from the study have been exposed. What the graduates think about the future of the Institution together with how they view the pupils of the eighties has received a place. It must also be mentioned that the graduates seem to view Healdtown as having prepared them for life
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Date Issued: 1989

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A possible mechanism for enzymic depilation of skins

- Brady, Dean

Authors: Brady, Dean
Date: 1989
Subjects: Chemistry, Technical , Tanning
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:3877 , http://hdl.handle.net/10962/d1001611
Description: Streptomyces fradiae is a bacterium which has been previously found to produce extracellular enzymes which are capable of wool degradation and skin depilation. Streptomyces fradiae 3739 and other strains of Streptomyces were found in this study to be able to degrade a keratin source (wool) to a considerable degree. However according to the evidence of SEM micrographs presented here the highly keratinised spindle cells of the paracortex are fairly resistant to protease attack, and it is the cementation material which binds these cells together which is initially degraded by the proteases. A large degree of correlation was found with the strains of Streptomyces studied, between the ability of the individual strains to degrade wool and the ability of their extracellular proteases to reduce the depilation load of sheepskins. With further analysis S. fradiae 3739 was found to produce at least one amylase and four or more proteases. The proteases as a group had maximal proteolytic activity in the 8.0-9.0 pH unit range, and were considerably thermostabilised by the inclusion of calcium ions into the reaction solution. The protease group was found to cause depilation of merino sheepskins. For comparative purposes a protease produced by a strain of Proteus vulgaris isolated from a staling hide with hair slip (natural depilation) was studied. The protease activity was maximal in the alkaline region between 8.0-9.0 pH units. Tbe protease appeared to be a single enzyme with a molecular mass of approximately 44 000 daltons. The protease was maximally active at 40°C, although it was only thermostable to 30°C. The enzyme was ineffectual as a depilant except when the skin was pre-treated with a strong alkali, preferably including sodium sulphite in the protease preparation. One of the most important differences between the extracellular proteases of S. fradiae and P. vulgaris was that the former were greater in variety and caused a greater decrease in the depilation load of sheepskins than the latter. Further research with mixtures of commercial proteases provided evidence that a synergistic depilatory effect occurs when proteases of complementary bond specificities are used in conjunction in enzymic depilatory preparations. Some form of strong alkali treatment of skins was found to be necessary to produce leather of the prerequisite quality when the skin was depilated by proteases, otherwise the skin was found to be depleted and stiff. Calcium hydroxide alone was found to be inadequate for this task, probably owing to the fact that it is less alkaline than the lime-sulphide mixture. The calcium hydroxide (lime) must therefore be used in conjunction with sodium hydroxide (which makes the solution as alkaline as that of the lime-sulphide solution) to produce leather comparable to that produced by the lime sulphide treatment. A combination of the information provided by the present research and that gleaned from the relevent literature allows for the construction of a model to represent the possible mechanism of enzymic depilation of skins, in which depilation is caused by the disruption of the basement membrane at the dermal-epidermal junction by the degradation of its constituent molecular components by general proteases, resulting in the removal of the epidermis and its associated wool or hair
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Date Issued: 1989

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