DAIRYING. 579 



one sample which had been kept for G or 7 weeks there was a loss of 5 

 to 6 per cent of the total solids, although only a small amount of acid 

 had been formed. 



Dr. Frankland's researches, he said, indicated very strongly that in 

 keeping milk in a bottle there was likely to be considerable difference 

 in the products of decomposition, according as the bottle was tightly 

 corked or the reverse. The products of the decomposition of milk were 

 so varied that it was impossible to fix any time allowance. The deter- 

 mination of calculations back of the alcohol and other bodies formed 

 seemed to be of doubtful accuracy. He had found in the case of koumiss 

 that it was possible to find an approximately constant factor for this, 

 though hardly accurate enough for analytical purposes. 



Mr. Allen reported some trials in which samples of milk were placed 

 in tubes hermetically sealed, one tube being opened each week. Other 

 samples were diluted with hydrant water and canal water and kept in 

 a similar way. The solids in the case of undiluted milk fell in 52 days 

 from 12.58 to 11.21 x)er cent, a loss of 1.37 per cent. The diluted milks 

 lost in the same time 1.44 and 1.46 per cent, respectively. Mr. Cassal 

 had noticed considerable diminution in the total solids on keeping milk. 

 There was no regularity about it, and he believed it was unscientific 

 and absurd to suppose there should be. The extent of the loss would 

 depend upon the temperature at which the samples were kept and on 

 the nature of the organisms which had obtained access to the milk. 



Mr. Yarrow had noticed a great loss in milk solids when the samples 

 were not evaporated as rapidly as possible. When there was a delay 

 in evaporation the loss amounted sometimes to as much as 2 per cent. 



The use of formic aldehyde for preserving milk for analytical pur- 

 poses was mentioned, and several analysts stated that they had 

 employed it successfully for some time j)ast. In one case it was stated 

 that 0.05 per cent would keep milk for a month and large quantities 

 almost indefinitely. Another analyst has found that the addition of 5 

 or 6 drops was sufficient to preserve a sample for a week. In Mr. 

 Stokes's laboratory one sample to which a 40 per cent solution of formic 

 aldehyde had been added was apparently fresh after keeping 9 months, 

 although there had been a loss of 0.4 per cent in the total solids and 

 0,2 per cent in the fat. Some experiments were announced as in prog- 

 ress which were intended to show the rate of decomposition in milk 

 when this preservative was added. 



Test of mechanical methods for determining milk fat by the 

 German Dairy Association {Milch Ztg., 23 {1894), ]^o. 46, p. 737).— 

 It will be remembered in the first test the judges found none of the 

 methods submitted satisfactory. In the second test for the prize of 

 3,000 marks ($750) the judges reported that none of the methods 

 entered fulfilled the requirements under which the prize was offered; 

 that is, gave results without the use of a chemical balance, which were 

 as accurate as the results of volumetric determinations. Although 



