182 
Proceedings of the Royal Society 
Found. 
Theory for 
[Ci 4 Hi 5 (N 02 ) 2 0 2 ] 3 Fe needs 
Carbon, 
51 -49 
51-59 
Hydrogen, 
4-82 
4-61 
N0 2 , . . . 
2816 
28-25 
Iron, 
977 
9-81 
Oxygen, . 
5-76 
5-74 
100-00 
100-00 
the ferric salt of di- 
■nitro-urushic acid. The acid itself is a 
bright yellowish solid, readily soluble in the usual solvents of 
urushic acid, and gives characteristic reactions with many metallic 
salts : those of silver, lead, zinc, and manganese are light yellowish 
precipitates ; those of copper and iron, greenish yellow ; and those 
of soda and potash, light brownish. The acid itself and its metallic 
salts are to some extent soluble in water, and more so in alcohol. 
The higher nitro-substitution products, are likewise yellowish 
substances ; their salts also seem to be characterised by their greater 
solubility in water and alcohol. 
When the action of nitric acid upon the yellowish substance is 
continued for several days, it finally goes into solution with copious 
evolution of nitrous fumes. On evaporating the solution over a 
water-bath, and cooling it, a large number of small granular crystals 
are formed. The mother liquor, when treated with more of the 
strong nitric acid and evaporated, yielded several crops of similar 
crystals. These crystals were mixed, cleaned from the small 
quantity of brownish oily matter, and recrystallised from ether 
several times until quite pure. On analysis the following result 
was obtained : — 
I. 
II. 
III. 
Mean. 
Required by 
theory for 
c 13 h 22 o 8 . 
Carbon, 
50-96 
50-82 
51-01 
50-93 ' 
50-98 
Hydrogen, . 
7T3 
7-20 
7-22 
7T8 
7-19 
Oxygen, 
41-91 
41-98 
41-77 
41-89 
41-83 
100-00 
100-00 
100-00 
100-00 
100-00 
The substance is an acid which contains no nitrogen, and no 
water of crystallisation. At 134° C. it melts without decomposition 
to a yellowish liquid, and at 126° C. solidifies in a capillary tube. 
