356 



DEDUCTIONS FROM ANALYSIS. 



can be calculated by actuarial methods from the actual 

 results. 



By a formula based on the theory of probabilities, the author 

 has calculated standards for each month below which milk 

 should not reasonably be expected to fall for both fat and solids 

 not fat, and in the case of fat has confirmed them by taking the 

 mean lowest percentage of fat in the milk sent out by the Ayles- 

 bury Dairy Company. 



These are 



TABLE CXXIV. 



According to the author's experience the limit of 3-0 per cent. 

 for fat is certainly reasonable for the mixed milk of a whole 

 herd, except perhaps in May and June ; such milk very rarely, 

 if ever, falls appreciably below this limit. It is far more frequent, 

 especially during July, August, and September, for milk to 

 contain less than 8-5 per cent, of solids not fat ; in the majority 

 of these cases, the author has found that at least 0-50 per cent. 

 of total nitrogen and 0-70 per cent, of ash was present, and 

 this experience has received much confirmation. Smetham and 

 some American observers have, however, found that even these 

 limits are somewhat too high for the milk of Dutch or Holstein- 

 Frisian cows, and the author has also found some samples which 

 do not conform to this rule. At the present time this breed 

 of cows does not form a majority of English milch-cattle ; on 

 farms where they are kept other breeds yielding milk of higher 

 quality are also milked. 



Multiple Standard. For all practical purposes the multiple 

 standard of 8-5 per cent, of solids not fat, 4-5 per cent, of 

 milk-sugar, 0-50 per cent, of total nitrogen, and 0-70 per 



