Intelligence afid Miscellaneous Articles. .543 



the loss should have been 3"00. Tlie salts of the preceding acids 

 ought to be represented by C" H^s M'^ O^ or by C^o H-» M O^. 



It is stated in chemical works, that sj'lvic acid crystallizes in four- 

 sided tables, and as pyromaric acid crystallizes in isosceles triangular 

 tables, the author has considered it as a different acid from the pre- 

 ceding ; but having an oj^portunity of seeing sylvic acid, the author 

 found it possessing the same form as pyromaric acid, and M. Mit- 

 scherlich made the same observation. 



Pimaric acid is the natural acid which flows from Finns mari- 

 tima. When it is heated for the purpose of separating the oil of 

 turpentine, a resin remains which is usually a mixture of pimaric 

 and sylvic acids. As to amorphous pimaric acid, it is possibly iden- 

 tical with pinic acid, if the latter be actually uncrystallizable in 

 alcohol. 



It becomes then requisite to examine the resins which flow from 

 other species of pines, to determine whether they contain pimaric or 

 sylvic acid, or whether the latter is not a product of the action of 

 heat upon the former. As to pinic acid, it must also be examined 

 whether it exists in the fresh resins of the pines, or whether it is 

 derived from a modification of pimaric acid, by the agency of time. 



It is to be remembered that crystallized pimaric acid is con- 

 verted either into amorphous acid, or pinic acid by the influence of 

 time, whereas the acid which has been fused undergoes no modifica- 

 tion. When pimaric acid is very pure, it may partly crystallize, 

 after having been fused ; if ten grammes be operated on, it assumes 

 a granular appearance like sugar ; when a smaller quantity is em- 

 ployed, it remains transparent and vitreous on cooling. 



The author states, that the acid which crystallizes from alcohol, 

 dissolves in about ten times its weight of this liquid, whereas the 

 same acid, when fused and then powdei-ed, immediately dissolves in 

 its own volume of alcohol, but almost directly se^iarates from it, and 

 becomes the crystallized modification, soluble in 10 parts of alcohol. 



Pimaric acid, crystallized by fusion, acts with alcohol nearly in 

 the same way as the acid which has been crystallized in it. 



Nitromaric Acid.' — M. Laurent formerly gave the name of azomaric 

 acid to a product which he obtained by treating pimaric acid with 

 boiling nitric acid for a long time ; and he has repeated the experi- 

 ment, continuing the ebullition for only seven or eight minutes. The 

 product washed with water, then dissolved in alcohol and precipi- 

 tated by water, gave by analysis similar results to those obtained in 

 the first operation : — 



First. Second. 



C 57-2 57-0 



H 5-6 5-9 



N 7-2 7-1 



300 30-0 



1000 1000 



This acid is yellow, amorphous and resinous ; by heat it softens, 

 fuses and decomposes. Its ammoniacal salt, which is very soluble, 

 dries in tran.sparent plates of an orange-red colour ; the salt of lead, 

 which is slightly soluble in alcohol, contains 32'8 to 33"4 of lead. 



