^58 1ACTIC ACIE*. 



becomes more acid. Thefe degrees of acidity are owing to a 



fmall quantity of acetic acid, formed by the aid of carbonic 



acid and alcohol remaining in the liquor, which muft naturally 



augment the acidity of the acid already formed in the milk. 



Whether the With regard to the fecond queftion, Whether whey exbi- 



falts in whey ,■'. . , . , . ' * , . 



render it four. Dlts acic * properties only on account of the falts it holds in 

 folution ? 



I have proved that the acid may be feparated from the faline 

 matters without expofmg the milk to the air for a certain time, 

 as Scheele has directed ; and the experiments I (hall relate in 

 this memoir will afford additional proofs. So that its acid 

 properties do not depend merely upon the falts it holds in 

 folution, and the laclic acid is not produced by a fermentation 

 fimilar to the acetous. 

 Zoonic acid by Though the action of caloric upon milk is generally known, 

 diftillingmilkj j p^u nevert helefs make an obfervation upon the acid ob- 

 tained by diftillation with a naked fire, which has for feveral 

 years been known by the name of the Zoonic Acid. 

 is acetous acid. If this acid be purified and combined with potafh, a fait 

 is obtained, which prefents all the characters of the acetate of 

 potafh. 

 Curd contains I muft alfo obferve the eheefy matter in which fome che- 

 P^° e fphate of mifts have been unable to find phofphate of lime, as announced 

 by Scheele. To obtain this, nothing more is neceffary than 

 ftrongly to heat this fubftance in a crucible after having well 

 wafhed it, and to calcine it to whitenefs. 



The refidue is a hard white matter, of which fome fmall 

 pieces, veined with blue, may be compared to the turquois. 



The nitric acid difiblves it without erTervefcence ; lime- 

 water and ammonia pecafion a flocculent precipitate of phof- 

 phate of lime. 



The oxalate of ammonia alfo deinonftrates the prefence of 

 lime. 



SECTION III. 

 Concerning the Serum of Milk. 



Examination of Being defirous of knowing whether there is any difference 

 whey feparated between the wheys obtained from milk by different fubftances, 

 2Ken'ts. eren I made ufe of the mineral acids, fome vegetable acids, falts, 



fiich as alum, the acidulous tartrite of potafh, &c. The coa- 

 gulating fubftance was employed in due quantity ; as I had 

 3 remarked, 



lime. 



