406 



silvery lustre, and much resembling benzole acid in aspect. They 

 sublime at 93 C. and melt at 153 C. ; but in aqueous solution the 

 acid volatilizes at ordinary temperatures. The crystals belong to the 

 oblique system, and usually occur in twin form. The measurement 

 of the angles, as determined at the author's request by Professor W. 

 H. Miller, is given in the Paper. 



Larixinic acid, like naphthalin and camphor, emits a sensible smell 

 at ordinary temperatures ; its taste is slightly bitter and astringent. 

 It very feebly reddens litmus, and a single drop of potash or ammo- 

 nia suffices to render a large quantity of it alkaline. It is very 

 soluble in boiling water, but takes 87 or 88 times its weight of water 

 at 60 to dissolve it ; it dissolves also in cold alcohol, but much more 

 largely in hot alcohol, and sparingly in ether. The crystals are in- 

 flammable, and burn with a bright flame, leaving no residue. 



Three analyses of the crystals gave the following results : 

 Calculated numbers. Found. 



C 20 = 57'14 57-13 57-06 57'09 



H 10 = 4-77 5-04 5-09 5-04 



10 = 38-09 37-83 37'85 37'87 



The carbon, hydrogen, and oxygen are therefore in the propor- 

 tions C 2 , H^ O x , and the author adopts C 20 , H 10 , O 10 as the most 

 probable actual multiples of these numbers. 



With ammonia, larixinic acid forms a combination so feeble as to 

 be severed by the mere volatility of the ammonia ; in this respect, as 

 well as in forming no hydrate, resembling pyrogallic and oxyphenic 

 acids. With potash it forms long flattish crystals of a reddish- 

 brown colour, which deepens on recrystallization. This combina- 

 tion is decomposed by carbonic acid ; it was not obtained of constant 

 composition. Larixinic acid gives no precipitate with lime-water or 

 saccharate of lime ; with baryta it forms a bulky, gelatinous preci- 

 pitate, like hydrated alumina, easily decomposed by carbonic acid, 

 and found from two experiments to contain 34 '92 per cent, of 

 baryta. 



Solution of larixinic acid gives no precipitate with basic or neutral 

 acetate of lead, perchloride of platinum (even with heat), nor with 

 nitrate or ammonio-nitrate of silver, although, when boiled with the 

 latter salt, it reduces the silver. 



