THE CHEMICAL COMPOSITION OF MILK IX THE CAPE 



COLONY. 



A Discrssiox of some of the Analytical Results obtained 



DURIN'G THE YeARS I907 — IQOg. 



By St. C. O. Sinclair, M.A. 



Under the Food and Drugs Act (Act No. 5 of 1890) of the Cape 

 Colony, no legal standards or limits for the chemical composition 

 of milk exist, nor has the Government the power to lay down 

 any such limits. Consequently in certifying to adulteration 

 the Public Analyst simply states that it is his. opinion that any 

 particular sample of milk is adulterated, and the standard he 

 adopts on such occasions is practically one of his own fixing. He 

 is quite at liberty to change his standard whenever he may deem 

 it right to do so. 



In the Government Analytical Laboratories, however, it has 

 been customary to adopt a minimum of 3% of fat, and 8*5% for 

 " solids- not- fat," in estimating deficiency of fat or the addition 

 of water in any specific sample of milk. « 



In the writer's capacity as Public Analyst, he has been asked, 

 both in the witness box and outside of it, to justify his action 

 in assuming these figures to be the limits for genuine milk sold 

 to the Public. 



It is one of the purposes of the present paper, therefore, to 

 show that the figures just stated are not without experimental 

 foundation and the standards of other countries have not been 

 arbitrarily adopted as has, on occasion, been contended. 



The writer has been questioned as to the seasonal variations 

 which occur in the composition of genuine milk as sold, as well 

 as to the difference in composition between milks of the morning 

 supply and evening supply : furthermore, questions have, from 

 time to time, been put as to the relative composition of the milk 

 yielded by cows of various breeds. 



Now, although it is not claimed that this paper is a complete 

 reply to all such queries as the above, and there are many reasons 

 why it should not be thus regarded, — still it is hoped that the figures 

 given below will show that there are some grounds at any rate 

 for the opinions expressed on the above points. 



As by far the larger proportion of samples analysed by the 

 writer have been taken in and about the Cape Peninsula, they 



