60 ANALYSIS AND ADULTERATIONS OF BUTTER. 



of the cow or by gross errors in the mode of feeding. Butter, 

 moreover, is never practically made from the milk of one 

 single cow, but of the united cream yielded by a whole herd, 

 and as in the case of milk analysis the excuse on the part of 

 the dealer cannot be considered sufficient, that an abnormal 

 cow is the producer of a suspected butter. 



The process for determining the percentage of the insoluble 

 fatty acids may of course be modified. Thus the idea may 

 occur to perform the washing of the fatty acids in a flask, 

 instead of upon a filter, and some may even be disposed at 

 first sight to give the preference to flask washing. So much 

 care and attention is required for our process, that a great 

 deal of trouble may seem avoidable, if instead of washing 

 the acids upon a filter for half an hour or an hour, by means 

 of boiling water, this washing is done simply by shaking the 

 melted mass with boiling water in a flask, allowing the oil 

 to rise to the top and to solidify, when it may seem easy to 

 pour off the liquid from the cake of acids. 



This modification is indeed strongly recommended by 

 Dr. Muter, and we are obliged to discuss this trivial question 

 at some length, because he insisted that only by the flask- 

 washing accurate results could be obtained. Dr. Muter 

 based this opinion especially on the fact that his results were 

 considerably higher than those published by us in the first 

 edition of this little work, and which, as we have mentioned 

 on page 46, showed on an average but 85*85 per cent, of 

 fatty acids, while Dr. Muter declared 88 to be a fair propor- 

 tion. He inferred that we had incurred a considerable loss 

 (which indeed we had). But he believed he had found the 

 sources of this loss, first in the firm adhesion of the fatty 

 acids to the basin, wherein the saponification takes place, 

 from which they could not, in his opinion, be properly 

 removed by washing ; and second, in the circumstance that 

 a filter could not perfectly separate the oily liquid from the 



