CHEESE MILK STANDARDS. 361 



Fat. About 5 grammes of the cheese are rubbed up in a 

 mortar with about 10 grammes of anhydrous copper sulphate. 

 The mixture is introduced into a Schleicher & Schiill's filter- 

 paper thimble and extracted with ether for eight or ten hours 

 in a Soxhlet extractor. The ether is then distilled off and the 

 fat weighed. 



Casein. -The total nitrogen is determined by the Kjeldahl 

 process," using about 2 grammes of cheese. The percentage 

 of nitrogen is then multiplied by 6 '38 and the product taken as 

 casein. 



These methods are those usually employed, but are not 

 entirely satisfactory. Attempts to differentiate between the 

 products of ripening have been made,f but they are too com- 

 plicated to be discussed here. 



MILK STANDARDS. The establishment of a standard by 

 which to judge of the quality and freedom or otherwise from 

 adulteration of a sample of milk has received much attention 

 and consideration. A few months ago (September, 1901) the 

 Board of Agriculture decided to take 3% of fat and 8-5% of 

 solids not fat, as the probable lower limit in the case of genuine 

 milk, and it was enacted by law that if a specimen did not 

 come up to these figures a presumption should be raised that it 

 was not genuine, by reason of the abstraction of fat or the 

 addition of water. While these values are much below the 

 average, and to that extent satisfactory from the producers' 

 point of view, it must be remembered that with morning milk, 

 when the night interval is much longer than the day one, 

 the fat content of genuine milk may often be below this 

 standard. Indeed, according to the experience of the author 

 during the very dry autumn of 1901, the mixed milk of dairy 

 shorthorn cows in the morning, was far more often below than 

 up to this standard. The cows were at pasture, but received 

 2ft). decorticated cotton cake each per day. For evening milk, 

 on the other hand, the standard, for fat is very much below the 

 average, and lower, perhaps, than the consumer has the right 

 to expect. 



* r. p. 04. f r. ('Imp. XIV. 



