150 Intelligence and Miscellaneous Articles. 



liquid is formed ; by long continued digestion, there is obtained 

 on cooling a large quantity of white opaque crystals, which when 

 boiled in water yield a sn)e]l of camphor. These crystals are the 

 camphoric acid of Lagrange, which gives with all bases insoluble or 

 slightly soluble salts. 



These crystals area chemical compound of camphor and cam- 

 phoric acid, which may be prepared directly by dissolving camphor 

 in camphoric acid melted at a very low heat. 



If this substance be treated a second time with concentrated 

 nitric acid, more transparent crystals of camphoric acid are ob- 

 tained, which give precisely the salts described by Brandes: when 

 a boiling solution of this camphoric acid was poured into one of 

 acetate of lead, camphorate of lead was formed, 100 parts of which 

 gave 67 7 of sulphate of lead ; analysis, however, rendered it probable 

 that the camphoric acid still retained some camphor in combina- 

 tion ; it was therefore again treated with nitric acid, and the action 

 was continued until no smell of camphor was perceptible when the 

 acid was boiled in water; 1105 parts of camphorate of lead gave 

 760 of sulphate. By analysis it yielded 



Hydrogen 6-981 



Oxygen 36-852 



Carbon 56-167 



100000 



Ibid, xlvii. p. 95. 



ON LACTIC ACID. BY BERZELXUS. 



Berzelius having ascertained that lactic acid is not acetic acid 

 and an animal matter analogous to the sulphovinic acid, nor a com- 

 pound of acetic acid and non-volatile animal matter, gives the fol- 

 lowing methods for obtaining it in purity : the acid alcoholic extract 

 obtained from milk or meat is to be dissolved in alcohol ; the solu- 

 tion is to be mixed with one of tartaric acid in alcohol as long as 

 precipitation takes place ; the mixture is to remain for 24 hours in 

 a cold place, in order that all the double tartrate which it contained 

 may deposit. The alcohol is to be evaporated, the residue dissolved 

 in water, and well powdered carbonate of lead added to it as long as 

 it dissolves, and until the solution has a sweet taste; it is then to be 

 treated with animal charcoal, and afterwards with sulphuretted hy- 

 drogen gas to remove the lead. The liquor is to be evaporated 

 until all the sulphuretted hydrogen is expelled, and then mixed with 

 well washed, moist, recently precipitated protohydrate of tin, with 

 which it is to remain for several days, and sometimes to be stirred. 

 The sublactate of tin formed is to be well washed and decomposed 

 by sulphuretted hydrogen, and the lactic acid resulting is the purest 

 which Berzelius has hitherto obtained: in this process much acid 

 however remains in solution, and is lost. 



Another method is to saturate the free acid of the alcoholic ex- 

 tract by means of carbonate of soda or potash ; the solution is to be 

 dried, and the mass heated on a sand-bath until it fuses, becomes 



brown. 



