252 LACTIC ACID. 



With frelh whey Experiment 1. If inftead of expofing whey to the air as 



little aci ' ' 

 tained. 



little acid is ob- Schee i e direds, the procefs be immediately performed on the 



frefh whey, a very fmall quantity only of acid is obtained, which 

 is lefs coloured and has a more animal fmell. 



This acid appeared to me to be uncombined in the milk, as 

 its quantity was fo fmall. 

 Ifbarytesor Experiment 2. Inftead of ufing lime-water and the oxalic 



ftrontianandful- ac ; d j ufed Darytes or ftrontian and the fulphuric acid. By 



phunc acid be J _ r ■* 



ufed inftead of U>is means I obtained an acid no lefs pure than that of the 



the lime-water Swedifh chemift. 



andoxalic acidof _ ... , , ... ._ . 



Scheeie the re- Lxpenment 3. 1 had likewile attempted to decompole a 

 Cult is equally laftate of potafh with acetate of lead, expecting to form a 

 Procefs" with delate of lead decompofable by the fulphuric acid; but the 

 acetate of lead precipitate thus formed is not a lactate of lead, for when a 

 un ucce s u . f u ffi c ient quantity of fulphuric acid is added for the purpofe of 

 decompofing it, no uncombined acid is fet at liberty. It ap- 

 pears that part of the oxide falls down with the animal matter; 

 and this compound is even to a certain degree foluble. It is 

 alfo found that the fluid always retains much acetate of lead in 

 folution. 



We therefore fee (hat though this procefs has been pointed 

 out as fuperior to that of Scheeie, it is certain that it cannot be 

 employed to obtain the lacVic acid. The following experi- 

 ments were made on the lactic acid of Scheeie. 

 Xatllc acidof 1- The intenfity of its colour may be diminifhed by grind* 



Schee'e ex- } n g a piece of red hot charcoal in a mortar, and pouring the 

 ladlic acid upon it. A quantity of fmall flakes were feparated 

 which rofe to the furface. The fluid was flightly boiled and 

 filtered, and the acid was then lefs coloured, and had lefs 

 odour. 



2. When this acid is diflilled in a retort acetic acid paffes 

 over and a thick yellow very acid matter remains. 



3. It may perhaps be thought that part of this acid becomes 

 changed into acetic acid by the afliftance of caloric, as Ber- 

 thollet obferves in his Chemical Statics. 



" The ternary acids, as this chemift obferves, may be 

 changed into acetic acid, when by the action of heat they 

 abandon part of their carbon, and their elements, which refift 

 this action lefs, are feparated by volalilazation." 



I have afcertained that great part of this acid previoufly 

 exifted in the fluid. 



3. The 



arained. 





