LIPIC ACID. 



best with this analysis, and with the atomic weight of the anhy- 

 drous acid, as it exists in adipate of silver, is C 14 H 9 O 7 + 

 2 (HO) = 20-875. 



14 atoms carbon, = 10-5 or per cent. 50-30 



1 1 atoms hydrogen, = 1-375 ... 6-58 



9 atoms oxygen, = 9-0 ... 43-12 



20-875 100- 



+ 



SECTION XII. OF LIPIC ACID. 



This acid is contained in the thick brown mother ley separated 

 from pimelic acid, as mentioned in the 10th section of this chap- 

 ter. When this liquid is farther evaporated, and left for some 

 time at rest, the lipic acid separates in large transparent crystals 

 as mentioned in the last section. 



The crystals are oblique elongated plates, usually grouped 

 together. This acid is much more soluble in cold water than 

 either of the two preceding acids. It dissolves readily in alco- 

 hol and ether. When heated in a retort, it may be distilled over 

 without alteration. When slowly heated, it sublimes in long 

 needles. When the temperature is raised cautiously, it gives out 

 water, and an anhydrous acid remains which melts between 

 284 and 293. Its vapour excites coughing, and is very suffo- 

 cating. 



Lipate of ammonia crystallizes in long prisms. When mixed 

 with a solution of chloride of barium, nothing happens at first ; 

 but in a few minutes crystals of lipate of barytes are deposited. 

 They are square prisms passing into octahedrons. In twenty-four 

 hours hardly any lipate of barytes remains in solution. 



Chloride of calcium behaves nearly as chloride of barium. 

 Chloride of strontium gives a kind of coronet. 



When the dry lipates are heated with sulphuric acid, lipic 

 acid is disengaged in needles. 



Lipate of ammonia does not precipitate the salts of manganese 

 nor of magnesia. It precipitates the salts of iron, copper, and 

 silver. According to the analysis of Laurent, to whom we are in- 

 debted for everything known of this acid, its constitution may 

 be represented by this formula, C 5 H 3 O 4 + HO = 9-25. 



