170 Br Latham, On the Composition of Albumen. [Feb. 6, 



can also be obtained artificially from the cyanhydrins of the alcohols 

 and ketones. 



2. Lactic acid is produced when a muscle dies, or when it con- 

 tracts, and by lactic fermentation from sugar. It can also be ob- 

 tained 



(i) by oxidising ethylic alcohol, treating the aldehyde so 

 obtained with hydrocyanic acid to form a cyanhydrin, and acting 

 upon this with acids or alkalis — 



2 H 5 . HO + = CH 3 . CHO + H 3 

 ethyl alcohol aldehyde 



(OH 



CH S . CHO + CNH = CH S . CH 

 aldehyde cyanhydrin 



CH 3 .CH {°^ + 2H 2 = NH 3 + CH 3 .CH S^ QK * 



ethidene lactic acid 



(ii) By converting ethene alcohol or glycol into a cyanhydrin 

 and boiling with acids or alkalis — 



| +HCl = H„0 + CH„r H2 ° H 



OH 2 .OH l u 



glycol chlorhydrin 



CH 2 {^ H2 ° H + KCN = KOI + CH 2 {^ 2 ° H 



cyanhydrin 



ethene lactic acid 



2. Leucine is very largely diffused in the animal organism, and 

 may be obtained by various processes from albumen, flesh, gelatine, 

 casein, &c.| 



By oxidising amylic alcohol with potassium chromate and sulphu- 

 ric acid, and distilling, we obtain amylic or valerianic aldehyde § — 



C 6 H n . HO + = C 4 H 9 . CHO + H 2 



amylic alcohol valerianic aldehyde 



Mixed with aqueous ammonia the aldehyde is converted into 

 valeral ammonia, and this digested with hydrocyanic acid and 

 hydrochloric acid is converted into leucine — 



* Fownes, Manual, p. 319. t Fowues, p. 319. 



J Watts, Dictionary, Vol. in. p. 574. § lb. Vol. v. p. 973. 





