M(1)47
LABORATORY BULLETINS.
The first of these made its appearance during the year, the subject being "Chinese Wood Oil". In it was collected all the scientific information on the subject likely to be of value to the merchant and exporter. Descriptions of all the heat tests are given in detail, together with Hong Kong, London, and New York Specifications for the pure oil, explanations of the various terms used in the Certificates, and a set of Tables for making certain calculations and corrections, determining the weight per cubic foot from the Specific Gravity, for freight purposes, etc.
It is hoped that shortly similar Bulletins will be ready on "Chinese Tin" and "Chinese Cassia Oil". Work on these is proceeding at present.
RESEARCH.
Questions as to the best methods for sampling Chinese ingot tin arose early in the year, and a considerable amount of work was done on the distribution of pure tin in the ingots after casting. If such an ingot were cast with one pouring from a large ladle, the purest tin would crystallise in the outer portion of the ingot, and most of the impurities tend to concentrate in the inner portion. Such ingots are, however, usually cast with six or seven separate pourings, and the exact distribution was therefore a matter of conjecture unless accurately determined. Portions of tin from every part of a tin ingot were analysed, and from the plotted results, a new method of sampling was worked out, which should give an accurate indication of the composition of the whole.
The presence of synthetic cinnamic aldehyde in Chinese Cassia Oil was raised during the year, also the presence in this oil of kerosene and alcohol as adulterants. Work was done on the best methods of detecting these substances, and correspondence has taken place with analysts in London and elsewhere, with the object of establishing a uniform and standard method for the examination of such oil for freedom from these adulterants. A method worked out in this Laboratory has been submitted for consideration as such a standard method.
Some work has been done on the detection of carboxy-haemoglobin in blood in cases of suspected carbon monoxide poisoning, and on methods for differentiating this from nitroxy-haemoglobin, a product liable to be formed by post-mortem decomposition.
A number of samples of rice, supposed to have been the cause of Beri-beri, were examined during the year, and in addition, an examination was made of all the ordinary commercial varieties on sale in the Colony, to ascertain what available kinds passed the minimum standard of 0.4% of Phosphorus.