some difficulty was encountered initially owing to uncertainly as to whether 'total' or 'soluble' lead content should be the basis for assess- ment of the problem, and it was finally agreed with agencies elsewhere that the total content would be used. Other commercial investigations of interest were in connexion with illegal removal of 'markers" from diesel oil, considerable ingenuity and chemical knowledge being exercised by operators in this criminal activity; it is hoped that the use of infra-red spectroscopy will achieve a more radical solution of this problem.
71. Work in the narcotics field increased considerably during the year, a marked feature being the lower proportion of actual narcotics in many of the mixtures seized. It would appear that much cruder methods are being used in illicit manufacture and that there is marked adulteration of the product before sale; this has required more complex, time-consuming and detailed analyses to evaluate the narcotic content of seizures.
72. In chemistry of food, the main emphasis was on the identifica- tion of preservatives. Apart from examinations for the contents of such well-known substances as benzoic acid or salicylic acid, the introduction as legally-permitted preservatives of the group of additives known as p-hydroxybenzoic acid esters has posed new technical problems, and various investigations and experimental work were undertaken in respect of these chemicals.
GOVERNMENT INSTITUTE OF PATHOLOGY
73. The expansion of medical services in Hong Kong and the increasing importance of laboratory investigations in both curative and preventive medicine have been reflected in the Government Institute of Pathology, whose work over the past ten years is illustrated in Figure 13. The total number of investigations undertaken by the Institute in 1964 represented a 34.4 per cent rise over the figures for 1963. This marked increase was due mainly to the full operation of the Queen Elizabeth Hospital with a consequent steady rise in demand for clinical pathology. while a further factor was the relatively short duration of the cholera outbreak which therefore did not interfere with routine services to an appreciable extent.
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SPECIMENS EXAMINED
1,000,000
200,000
GOGLODO
+400,000
200,000
Bacteriology
FIGURE 13
WRK OF GOVERNMENT INSTITUTE OF PATHOLOGY 1933-64
33 56
513
59
YEAR
60 61 62
12
14
74. Apart from routine clinical work, the year-round monitoring of nightsoil and of cases of gastro-enteritis for cholera vibrios was continued, together with other epidemiological studies of which the most notable were the intensive bacteriological investigation in connexion with the 'Temple Street Well' and the assessment of the value of Vi antibody titres in the control of typhoid fever. Other projects included phage typing of El Tor vibrios and studies of the characteristics and distribution of non-agglutinable vibrios. In tuberculosis, bacteriological investigations were carried out, in collaboration with laboratories in Britain, during controlled trials of two anti-tuberculosis drugs, ethiona- mide and isoxyl.
Clinical Pathology
75. The histopathology section of the Queen Elizabeth Hospital laboratories opened in May 1964 and shortly thereafter the Institute accepted responsibility for all routine post-mortem examinations re-
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