12
than that sold in others but in no city is uncertified milk safe for consumption until it has been subjected to some process of sterlisation. Realising this the authorities of Toronto, New York and many other cities have decreed that no milk shall be sold unless it be "certified" or sterilised by pasteurisation or otherwise.
12. It is generally admitted that the risks of milk contamination are less in a dairy which employs educated Europeans than in one which employs uneducated Chinese. The risks in Toronto are therefore less than in the Hong Kong Dairy Farm and very much less than in most of the small dairies in the Colony. If it be necessary to safeguard the purity of milk in Toronto by compulsory pasteurisation it is many times more necessary in Hong Kong.
13. Compulsory pasteurisation of all locally produced milk is recommended.
Appendix D.
The case for Notification of Dysentery.
1. The value of notification lies in the assistance it offers in discovering the distribution of infection. It affords opportunity for early discovery, early enquiry and early action and it supplies the data necessary for the preparation of statistical records of public health importance.
2. The decision as to whether or not a particular disease should be made notifiable must be based on the relation it bears to the public health of the community con- cerned.
3. It is generally agreed that certain diseases should always be listed as notifiable but there are others with regard to which opinions differ.
4. A disease normally of small importance from the public health point of view may locally outbreak to such an extent as to cause serious concern.
In such a case it may be found advantageous to make it temporarily notifiable.
5. The diseases concerning which there is general agreement are plague, cholera, yellow fever, small pox, typhus, cerebro-spinal meningitis, diphtheria, scarlet fever and enteric.
6. The diseases over which opinions differ may be said to be tuberculosis, leprosy, cancer, malaria, chicken pox, whooping cough, influenza, diarrhoea and dysentery.
7. Dysentery is not listed as a notifiable disease in Great Britain, India, Malaya or Hong Kong and it is not one of the diseases mentioned by the International Sani- tary Convention, but it is listed as such in New Zealand, in certain provinces of Canada and Australia, in Germany, France, Panama, Japan, Nanking, Peiping and Shanghai.
8. The difference of practice in different countries is due partly to differences in local conditions with regard to risks of epidemics from particular types of dysentery partly to conflict of opinion as to the value of a symptom common to a number of diseases as an index of the presence of any one of them.
9. The respiratory diseases bronchitis, pneumonia, whooping cough, influenza and tuberculosis have a common symptom cough. In the same way the intestinal diseases amoebic dysentery, Shiga dysentery, the dozen kinds of Flexner dysentery, Schmitz dysentery and bilharzia or schistosoma dysentery have one common symptom viz., "dysentery" that is to say a diarrhoea accompanied by mucus and blood in the stools.