LACTIC ACID. 



263 



5. The fame phenomena take place, but more ftrikingly, 

 if whey bedifhlled which has been expofed to the air at the 

 temperature of 15 or 20 degrees (60 and 68 Fahrenheit) for 

 about a fortnight. The firft product is a clear tranfparent fluid 

 of an acid fafie, and odour of alcohol, which when combined 

 with potafh, forms an acetate. 



If alcohol be added to what remained in the retort, it be- 

 comes coloured. After decantalion and diftillation, an acid is 

 found in the retort of a peculiar odour, animalized, and re- 

 fembling the preceding; but the acid contains a very fmall 

 quantity of phofphale of lime. 



Thefe experiments confirm the obfervations I have made : It is a mixed 

 1. That a mixed acid is obtained by the procefs of Scheele, * 

 and 2. That an acid exifts in milk and in whey recently 

 prepared. It remains to (hew the nature of that acid. For 

 that purpofe I prepared the lactic acid according to the procefs 

 of Scheele with every neeeffary precaution. I even ascertained 

 the purity of my alcohol, which having been diftilled from 

 muriate of lime, marked 40 degrees of the aerometer of Reau- 

 mur. 



The laclic acid when diflblved in alcohol was fubmitted to When diflblved 

 diftillation. There pafled into the receiver an alcohol which >n alcohol lonw 

 reddened the tin£ture of turnfole. wit h the f ir j u 



When the acid was totally deprived of alcohol the difiilla- Lactic acid re- 

 tion was flopped. The la&ie acid of Scheele remained of a mained. 

 yellow colour and very four tafle. 



Experiment 1. I mixed quick lime with this concentrated It gave out am- 

 acid, and a difengagement of ammonia took place.* moma oy lime. 



Experiment 2. If a lactate of potafli be formed and evapo- Lactate of pota/h 

 rated by a gentle heat, a brown matter is Separated, which is leaves P ruffic 

 infoluble in water. This being afterwards heated iu a cruci- 

 ble, the fait fwells up and emits an animal odour. The pre- 

 fence of pruffic acid was proved by diflblving the remaining 

 matter in water and adding a fmall portion of the fulphate of 

 iron in folution. 



* I had before afcertained the prefence of ammonia in this acid. 

 I announced it on the 15th Nivofe to the Society of Pharmacy. Mr, 

 Vauquelin, who was not acquainted with this fact, informed me at, 

 the reading of the firft part of this memoir that he had alfo afcer- 

 tained the prefence of an animal matter in the la&ic acid of Scheele. 



Experiment 



