1871.] 



Compounds of the Orcins. 



413 



Barium trinity o-orcinate. — Trinitro-orcinic acid was dissolved in 400 or 

 500 parts of boiling water and an excess of barium carbonate added, the pale 

 yellow solution filtered from the excess of carbonate and set aside. On 

 cooling, the solution formed a semisolid crystalline pap, consisting of fine 

 bright yellow needles of the barium salt. The air-dried salt lost 10*7 per 

 cent, at 100°, and became of an orange-red colour, but regained its original 

 colour on exposure to moist air. A barium determination was made of 

 the salt dried at 100°. 



I. '235 grm. substance gave * 139 grm. barium sulphate. 



II. '328 grm. substance gave "194 grm. barium sulphate. 



Theory. I. II. 



C 7 = 84 . . .. . • . . 



H 3 = 3 



Ba"=137 = 3477 34*78 34*79 

 N 3 = 42 

 O, =128 



394 



The orange-coloured anhydrous salt has the composition 



C 7 H 3 ( N ^3 J 2 , and the yellow needles ° 7 Hs (N< ^ j 2 + 3H 2 0. 



Calcium trinitro-orcinate, prepared by neutralizing the acid with calcic 

 carbonate, is very soluble in hot water, and crystallizes out on cooling in in- 

 terlaced yellow needles, which are rather soluble in cold water. It is but 

 slightly soluble in hot alcohol ; and the solution forms a gelatinous mass 

 on cooling. 



Magnesium trinitro-orcinate is very soluble in cold water, but less so in 

 spirit. It crystallizes in minute orange needles. 



Lead trinitro-orcinate. — This salt was prepared by dissolving the pure 

 trinitro-orcinic acid in 1000 parts of water strongly acidulated with acetic 

 acid, and adding a solution of lead acetate likewise strongly acidulated, 

 when the lead trinitro-orcinate came out as a bright yellow crystalline pre- 

 cipitate, consisting of tufts of microscopic needles, which are very tough 

 and difficult to reduce to powder. It is almost insoluble in cold water, 

 slightly soluble in hot. It is solubie in hot acetic acid, from which it 

 crystallizes unaltered. It is insoluble in alcohol. If alcoholic solutions of 

 trinitro-orcinic acid and lead acetate be mixed, the lead-salt is obtained as a 

 yellow amorphous precipitate. 



Dried at 100° it gave the following results : — 



I. '319 grm. substance gave '207 grm. plumbic sulphate. 



II. '536 ~rm. substance gave "348 grm. plumbic sulphate. 



III. -339 grm. substance gave -221 grm. plumbic sulphate. 



Mean. 

 34-78 



VOL. XIX. 



