MILK. 437 



count of it, with a receipt for making it, was inserted by Dr 

 Grieve in the first volume of these Transactions. A little very sour 

 milk is added to the mare's milk that is to be con verted into koumiss, 

 and the whole milk must be frequently and thoroughly agitated 

 several times during the process. The koumiss must always be well 

 agitated just before it is to be used. The Tartars consider this 

 liquid as highly nutritive and medicinal. There is an elaborate 

 history of this liquid, together with a set of experiments on the 

 fermentation of sugar of milk, by M. Schill, in the thirty-first vo- 

 lume of Liebig's Annalen der Pharmacie, (page 152.) Many 

 chemists had failed in their attempts to ferment milk and obtain 

 alcohol from it. Schill, however, succeeded. I have been in- 

 formed by the late Sir John Sinclair that koumiss is made both 

 in Orkney and Shetland nearly in the same way as in Tartary. 

 Of course, they will use cow's milk in these islands instead of 

 mare's milk. 



From the experiments of numerous chemists it had been con- 

 cluded that sugar of milk is incapable of fermenting, and of 

 course of yielding alcohol. But Scheele had long ago observed 

 that milk ferments, and gives out a great deal of carbonic acid 

 gas.* And Schill found by experiment, that 100 parts of su- 

 gar of milk by fermentation may be made to yield 36*101 of ab- 

 solute alcohol, f 



A set of experiments was made by MM. Boussingault and 

 Le Bel, to determine the effect of various kinds of food upon 

 the quantity and quality of the milk given by cows4 They have 

 not given satisfactory results. Because the quantity of milk di- 

 minishes in proportion as the time after calving increases. They 

 deserve a place, however, as giving the quantity and quality of 

 the milk of the same cow during a period of 302 days. 



Scheele's Opuscula, ii. 66. f Annalen der Pharm. xxxi. 171, 



Ann. de Chim. et de Phys. Ixxi. 65. 



