Milk. 163 



milk never fell below 9-3 per cent., and that the fat never 

 falls below 3 per cent. The English Society of Public 

 Analysts adopted limits rather more favorable to the milk- 

 man, namely, 9 for the solids not fat and 2-5 for the fat. 

 If a milk contained less than 9 per cent, solids not fat, it 

 was considered watered, and if less than 2 5 per cent, fat 

 without a corresponding decrease of solids not fat, 

 skimmed. 



The English Public Analysts almost universally adopted 

 Wanklyn's method of milk analysis. The German 

 chemists, on the other hand, usually mixed the milk with 

 some insoluble powder, like sand or plaster of Paris, during 

 the drying, for the purpose of obtaining the residue in a 

 fine state of division, in which condition the fat is more 

 easily removed by ether. Of late years, too, various appli 

 ances for continuous extraction, such as Soxhlet's, came 

 into use. These methods are found to extract the fat from 

 a milk residue more completely than Wanklyn's process ; 

 for milk drying up in a dish forms a horny mass, only 

 penetrated with difficulty by solvents. Chemists using 

 these processes got higher percentages of fat than those 

 who used Wanklyn's. He, for example, gave 3*2 as the 

 average percentage of fat, but Vieth, as the average of 1,300 

 "analyses made in 1887, gives 3 - 82 as the average, and we 

 found in Canada the average 3 • 86 per cent, of fat. Now 

 this increase in fat lowers the solids not fat, and it gradual!}- 

 became evident that 9 per cent, of solids not fat was too 

 high a limit. 



In 1883, there was a famous milk case tried in Man- 

 chester, in which a milkman appealed from a conviction of 

 selling adulterated milk. The public anatyst found S-62 

 per cent, solids not fat b} 7 Wanklyn's method, and reported 

 the milk adulterated. A great number of analysts were 

 called on both sides, and a good deal of evidence of a very 

 conflicting character was given, the result being that the 

 conviction was dismissed. 



This contradiction of testimony drew great attention to 

 the subject of milk analysis and milk limits. A committee 

 of the Society of Public Analysts was appointed to investi- 



