M 104
In December a sample of suspected food in a case of attempted poisoning was found to contain oz. of caustic soda. The taste of the food had proved to be sufficiently unpleasant to deter anyone from partaking of it.
A number of articles were submitted by the Police in March in connection with a case of attempted arson in Yaumati. Traces of kerosene found on many of these substantiated the charge against the defendant. Seven samples of fluid found in a house in Wing Lok Street where arson was suspected, proved on analysis to be a mixture of kerosene and petrol.
Work was done during the year on several cases concerning forged bank-notes, in two of which Straits $1 notes were involved. Microphotographs taken of the suspected and genuine notes, together with micrometric measurements, demonstrated that the former were counterfeit, and that at least two separate sets of plates had been used in the preparation of them.
In December a number of articles were submitted by the Police in connection with a charge of counterfeiting Hong Kong coins. Coin moulds, counterfeit coins together with various chemicals and pieces of metal were examined. The coins were composed of a tin-antimony alloy.
In two cases of corrosive fluid throwing, garments were submitted for the examination of stains. Hydrochloric acid was found in one case and a mixture of hydrochloric and nitric acids was found in the second. A jacket submitted in an alleged pepper-throwing case was examined. The dust from the front and sides of the garment when microscopically examined showed a considerable proportion of pepper.
A number of five cent receipt stamps were submitted in cases where it was alleged that attempts had been made to obliterate the cancellation. In several instances it was demonstrated that attempts to do this had been made.
## RESEARCH WORK
In connection with the application of electrical conductivity methods to the investigation of cases of drowning, conductivity measurements have been made on a large number of specimens of various bodily fluids. Amongst these were a considerable number of ascitic fluids, the work on which was done in collaboration with Prof. Gerrard of the Hong Kong University. Measurements of the total chloride in terms of sodium chloride, of the electrical conductivity in reciprocal megohms and of the total electrolytes calculated from the conductivity were carried out. In some instances this was supplemented by determinations of the blood sugar and blood urea nitrogen from the same cases.