i MILK 113 



twenty-four hours later. Should this be impossible, then another 

 day must elapse in all, forty-eight hours and under certain 

 circumstances it may be necessary to wait until the evening of 

 the third day. If the suspected sample is from mixed morning's 

 and evening's milk, then the stall sample must likewise be 

 taken from similarly mixed milk. 



In cases of this sort the assumption is made that the mixed milk 

 of several cows and of the same milking (morning or evening) 

 does not alter in solids not fat from day to day. This assump- 

 tion is, however, not always to be relied upon, but the 

 exceptions are very few indeed where there has been no change 

 in the food or in the treatment of the cows from the time of 

 taking the milk which was analysed to the time of taking the 

 sample in the stall. 



The stall sample must be taken in the presence of two 

 impartial witnesses, one of whom takes his stand near to the 

 churn into which the whole of the milk is poured, whilst the 

 other stands beside the milker and sees that the can is empty 

 when the milking begins and that the cows are milked clean. 

 After an average sample has been taken, it is sealed up by the 

 witnesses and sent, with any remarks they have to make, to the 

 analyst. If now the analysis shows the milk to be of normal 

 composition, whilst the previous sample from the same animals 

 and similar time of milking was abnormal and indicated 

 adulteration, either by addition of water, removal of cream, or 

 both, there is no doubt that such has been practised. 



It is only in the case of considerable adulteration that the 

 fraud can be constated with certainty without the help of the 

 stall test. In all other cases it is difficult to arrive at a safe 

 conclusion without taking a sample from the stall. There is 

 the further advantage in taking this stall sample that the 

 degree of addition of water or removal of cream can be calcu- 

 lated with its help. 



1. Calculation of the Added Water. 



When calculating the amount of water added to milk, it is 

 best to start from the amount of solids not fat, for these are 

 subject to relatively smaller variations than are the specific 

 gravity and particularly the quantity of fat. 



