REPORT OF THE CHEMIST. 119 



the Steppes of Eussia to Vienna for tbe purpose of usin^ their milk for 

 kiiinys, found its percentiige of lactose to be 7.20. On the other hand, 

 ordinary mares that were kept at work gave a milk containing only 5.95 

 ])er cent, sugar. 



The quantity of milk-sugar in mare's milk is great, but there is a de- 

 llciinicy of fat and other solids. It appears to contain fully ?^9 per cent, 

 water, while cow's milk does not have more than 87 per cent. 



The process of manufacture is not uniform. In the Orient the mare's 

 milk is placed in leathern vessels; to it is added a portion of a ]>revious 

 brewing, and also a little yeast. In thirty to forty-eight hours the pro- 

 cess is complete. During this time the vessels are frequently shaken. 



In tlie saniples analyzed, the milk was treated with a lactic ferment 

 and yeast. After twenty-four or forty-eight hours' fermentation, the 

 kumys was bottled. Tbe bottles were kept in a cool place, not above 

 50° F., and in a horizontal position. When shipped to me they were 

 l)acked in ice. After they were received in the laboratory they were 

 kept on ice until analysed. 



METHOD OF ANALYSIS. 



Carbonic dioxide. — The estimation of the carbonic dioxide was a prob- 

 lem of considerable difiiculty. It was evidently impracticable to at- 

 tem])t opening the bottle and determining the gas in a portion of the con- 

 tents. Fortunately I had access to a large balance which would turn 

 with a milligram. On this was weighed the whole bottle, into the cork of 

 which was inserted a sto])-cock such as is used sometimes with a cham- 

 pagne bottle. With the bottle of kumys were also weighed two drying 

 tiasks, containing concentrated sulphuric acid with their connections. 



Having obtained the weight of the whole, the gas was allowed toes- 

 cai)e slowly from the stop-cock and to bubble through the sulphuric 

 acid in the washing bottles. 



These bottles, previously to being weighed, were filled with the gas 

 from an ordinary carbonic dioxide generator. After the gas had almost 

 ceased to flow the bottle of kumys was frequently shaken. It was also 

 placed in a pail of water having a temperature of 30° C. After half an 

 hour the gas ceased to come over. 



The whole ajiparatus was again weighed. The loss of weight gave 

 the quantity of free carbonic dioxide in the sample. After the analysis 

 was completed the volume of the bottle was measured. It is fair to as- 

 sume that at 30° C. the kumys still contained an equal volume of dis- 

 solved CO2. In determining the total CO2 this volume, or its equivalent 

 weight, was added to that obtained by direct determination. 



By this method the CO? dissolved under pressure in the bottles is es- 

 timated separately from that which the kumys contains in solution un- 

 der the weight of one atmosphere. Since it is of no importance to sep- 

 arate the gas into these two portions, I have given it altogether in the 

 tables — in volume — by weight and in percentage by weight. 



Acidity. — The samples examined showed under the microscope the 

 acetic ferment and a portion of the acidity was therefore due to acetic 

 acid. It is the custom in giving the results of analyses of kumys to 

 represent the whole of the acidity as due to lactic acid. If ordinary 

 yeast is used, and it generally is, it is x>ossible that acetic acid may be 

 formed. This appeared to be the case with the samples in question, 

 since on distilling them a larger percentage of acid was found in the dis- 

 tillate than could have been expected had lactic acid only been i)resent. 



