Intelligence and Miscellaneous Articles. 1 5 1 



brown, and gives a urinous smell ; and when this has been succeeded 

 by that of herring or roast meat, the mass is to be taken from the 

 fire and treated with animal charcoal til) it becomes colourless ; it 

 is then to be filtered, evaporated to dryness, and dissolved in alco- 

 hol ; the solution is to be decomposed by tartaric acid, the excess 

 of which is to be removed by carbonate of lead, and the lead by sul- 

 phuretted hydrogen, and the residual solution then evaporated. In 

 this way colourless acid is obtained, but it contains extractive mat- 

 ter, and is less pure than by the first method. 



Lactic acid obtained by either of these methods is colourless, 

 inodorous, has a sharp burning taste, which is quickly diminished 

 by the addition of water; so that after having slightly diluted the 

 acid, it has scarcely any taste. Evaporated at 21'2° till it loses no- 

 thing more, the acid obtained with protoxide of tin flows with diffi- 

 culty like a fat oil ; that procured by the second process mav be 

 inverted in the containing vessel without leaving it ; both liquefy in 

 the air; the first becomes fluid, the second syrupy. When strongly 

 heated it becomes brown, boils slightly, and gives a suffocating smell 

 like that of heated oxalic acid ; it then blackens, swells, smells like 

 burnt vegetable matter, and leaves a porous coal. It dissolves in 

 alcohol in all proportions, but sparingly in aether. — Jnn. de Chim. 

 et de Ph. xlvi. 420. = 



ON THE PROPERTIES OF THE LACTATES. BY THE SAME. 



The lactates obtained by Scheele were all like gum and uncry- 

 stallizeable, except the lactates of magnesia and zinc, which may be 

 crystallized; they are generally soluble in alcohol, but sometimes 

 rather slowly, on account of the different extractive animal matters. 

 When they contain an excess of base they dissolve with difficulty 

 in alcohol, but readily when saturated. By destructive distillation 

 they yield an acid liquor, the smell of which resembles that of the 

 tartrates [pyrotartrates?], an inflammable oil and various gases. 

 The lactate of potash prepared with lactic acid purified by protox- 

 ide of tin gives, when evaporated at 175°, a saline crystalline mass, 

 which li(|uefies in the air. 



Lactate of soda does not crystallize as long as the acid is in 

 excess ; but when it is saturated by carbonate of soda, dried and 

 dissolved in alcohol evaporated at 1 54°, a crystallized salt is obtained, 

 covered with a hard colourless transparent mass, which becomes 

 moist in the air. 



Lactate of ammonia, provided excess of ammonia be retained 

 during the evaporation, exhibits traces of crystallization. The am- 

 monia is dissipated, and leaves an acid deliquescent salt. By dis- 

 tillation it loses the greater part of its ammonia before it begins to 

 decompose, as Scheele has already observed. 



The lactates of barytes and lime are known only as non-dcliqnes- 

 cent transparent fjummy masses; tiie magnesian salt, evaporated at 

 a gentle heat, yields granular crystals, as Scheele has remarked; 

 but by a mor • rapid evaporation it becomes a gummy non-deliques- 

 cent mass. The lactate of ammonia and magnesia crystallizes m 

 acicular prisms, which do not alter in the air. It may be obtained 



by 



