Iiitelli geJice and Miscellaneous Articles. 235 



lime, which requires only to be successively treated with water 

 and alcohol to be perfectly white. According to M. Corriol, nux 

 vomica yields from 2 to 3 per cent, of this salt, and it alsocontiiinslac- 

 tate of magnesia. These salts were purified with the greatest facility, 

 and furnished an acid identical with the lactic acid of beet-root, rice 

 and milk. 



When concentrated in vacuo until it loses no more water, lactic 

 acid is a colourless liquid of the consistence of syrup : its density at 

 about 68° Fahr. is 1 215. It is inodorous: it is extremely acid. Ex- 

 posed to the air it attracts moisture : water and alcohol dissolve it 

 in all proportions ; sulphuric aether takes it up more sparingly. 



When boiled with concentrated nitric acid, it is converted into 

 oxalic acid. Two drops, added to about 1500 grains of boiling milk, 

 immediately coagulated it ; but a larger quantity had no effect on 

 cold milk : a small portion also coagulates albumen. It rapidly dis- 

 solves bone phosphate of lime. When boiled with acetate of potash it 

 expels acetic acid: if added to a concentrated cold solution of acetate 

 of magnesia, it soon occasions a granular white precipitate, which 

 is lactate of magnesia, and a smell of vinegar is produced. 



Lactic acid also gives a precipitate of lactate of zinc when poured 

 into a strong solution of acetate of zinc. Lactate of silver is de- 

 composed by acetate of potash, and acetate of silver is deposited in 

 abundance. Lactic acid does not occasion any turbidness in lime, 

 barytes or strontia water. 



Of all the properties of lactic acid, the most remarkable, and 

 which would be alone sufficient to characterize it, is the phenomenon 

 of its sublimation. When the acid, of the consistence of a syrup, is 

 gradually and cautiously heated, it first becomes very fluid, soon 

 afterwards coloured, and yields inflammable gases, vinegar, a coaly 

 residue, and a great quantity of a concrete white substance, the 

 taste of which is both acid and bitter. This substance, pressed be- 

 tween folds of blotting paper, and thus freed mechanically from an 

 odorous substance, is very soluble in boiling alcohol, from which it 

 precipitates on cooling in the form of rhombic tables, which are of a 

 brilliant white colour. These crystals are inodorous ; their taste is 

 acid, but much less so than the liquid lactic acid, which is probably 

 owing to their slight solubility. They fuse at about 225° Fahr., the 

 liquid resulting does not boil at a lower temperature than 482°, and 

 emits white irritating vapours : on exposing a cold body to them, they 

 condense in the same crystalline forms as those which produced 

 them. These vapours are inflammable, and burn with a pure blue 

 flame. If the operation is carefully conducted, there is no residue 

 in the vessel in which the sublimation is effected: all the acid rises 

 without alteration. These crystals repeatedly fused and sublimed 

 do not lose any water. 



The tendency of the sublimed lactic acid to crystallize is ex- 

 tremely remarkable, especially in the dry way. Thus, when it is 

 rated in a glBM tube, although great agitation be used, the acid 

 cannot be prevented from crystallizing in perfectly well-formed 

 crystals. 



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