J44f LACTIC ACID. 



noife, indicating (tig pretence of an elaftic fluid. Upon 

 (halting the bottle, a greater quantity of gas was difengaged, 

 which being collected and examined, had the fame characters 

 as carbonic acid. 



The fluid as well as the curd had a fharp acid tafle, which 

 became lefs pungeut, as the carbonic acid was difengaged by 

 agitation. 



The fluid, after having been heated, did not appear to be 

 more acid than ferum, obtained by expofing milk foT the fame 

 time to the air. 



The fame experiment was made with milk which had been 



boiled about half an hour, and the refults were the fame. 



Exp. 7. Quail- Experiment 7. The cheefy matters of the third, fourth, and 



ties of the fifth experiments, differ effentially in tafle and confidence, 



cheefy matters. Thafc of ^^ ^ j( . ^ ^ fifm . ^ of Nq _ fc ^ more 



divided, lefs dry, and partly foluble in water; and laflly, that 

 obtained in the experiments No. 5 and 6. is not clotted, but 

 is more light, and does not unite into a mafs, till after feveral 

 hours. 



The cheefy matter, therefore, requires particular proper- 

 ties, according to the fubftances and the procefles employed 

 to feparale the ferum. 

 Dedu&ions from Thefe firfl experiments lead us to the following reflections, 

 that, I . Milk does not require to be decompofed, in order to 

 manifeft the prefence of an acid. 2. That this acid is mixed 

 with falts, fugar, and animal matter. 3. That the acid in 

 milk is difengaged, though it is not very perceptible, but by 

 re-agents. 4. That the contact of the air is not neceffary for 

 ieparating the conftituent parts of milk. 5. That the coagu- 

 lating fubftances merely facilitate the feparation of the cheefe, 

 either by forming a new compound, or by more immediately 

 condenfing the particles together, when the cheefy matter re- 

 quires new properties: or laflly, by expofing the milk to the 

 air. By degrees, a part of the fugar of milk is decompofed ; 

 carbonic acid is formed, of which one part is difengaged, and 

 the other facilitates the feparation of the curd ; caloric alfo 

 favours the attractions of coagulating matters for the curd. 

 They all act differently, for alcohol, which alfo pofteffes this 

 property, affords other refults ; the curd being to a certain 

 point foluble in water. We cannot therefore as chemifts have 

 atcTibed thefe effects to the folution of thofe fubftances in 

 water, and their greater attraction for the liquid than is ex- 

 erted by the cheefy matter itfelf. 



(To be continued.) 



thefafts. 



