REPORT TO THE MEDICAL OFFICER OF HEALTH 
OF THE INVESTIGATIONS AND ANALYSES MADE 
BY THE CORPORATION BACTERIOLOGIST 
The work of the Bacteriologist comprises : — 
(a) Examination of food stuffs of various kinds. 
(b) Regular examination of water supplied to the City. 
(c) Examinations into suspected cases of rabies, anthrax, glanders, &c. 
(d} Examination for diagnostic purposes in suspected cases of diphtheria, 
typhoid fever, tubercular sputum, &c. 
(e) Special investigations. 
In the examination of food stuffs the following general methods are employed : — 
Samples of milk and samples of water are collected in sterilized bottles, and if 
they cannot be examined immediately they are kept in a refrigerating chamber. 
(i) Preservatives in Food. In view of the increasing use of preservatives of 
various kinds in food stuffs, and the difficulty which has been experienced in proving 
in Courts of Law the limit beyond which it was dangerous to extend their use, the 
Medical Officer requested the Bacteriologist to undertake some exact experiments into 
the physiological action of boracic acid and formalin, as these, especially the latter, 
were found in foods likely to be used for infants and young children. 
A series of experiments were conducted by Dr. Annett, which consisted in 
feeding kittens of three weeks old upon milk containing minute but definite proportions 
of the preservatives in question, and the observations extended in each case over a 
period of from six to seven weeks. With regard to the boracic acid, {a) Five kittens 
were fed upon milk containing 10 grains to the pint ; (b) Five kittens were fed upon 
milk containing 5 grains to the pint ; (c) Five kittens were fed upon perfectly pure 
milk, the kind of food being the only difference in the treatment of the animals. In 
every case a supply of milk was always available for the kittens to lap. 
Results. The group (a) fed with 10 grains of boracic acid to the pint showed 
rapid emaciation, diarrhoea, and death resulted in from three to four weeks ; the 
kittens treated with 5 grains showed results almost similar. The remaining five 
kittens fed with pure milk increased in weight and remained healthy. 
With regard to the second series of milk, viz., that treated with formalin, the 
proportions of formalin, which is a very powerful antiseptic, were used as follows : — 
Five kittens were fed with milk containing 1 part in 50,000 of milk, five with 1 in 
25,000 of milk, and five with 1 in 12,500. As in the preceding cases, there was a 
