CETRARINE. 
57 
colors. It belongs, therefore, to the electro-negative organic 
substances. Alcaline solutions dissolve cetrarine with great 
facility, but these combinations have great tendency to change 
into ulmates; thus, the best means to obtain them pure, is to 
dissolve as much cetrarine as possible in a very weak alkaline 
solution, and add afterwards an acid, the acetic acid especially, 
until the liquid becomes slightly acid. The ammoniacal salt, 
especially, is obtained very easily in this manner. It is 
yellow and almost crystalline in appearance. By repeated 
solutions in boiling alcohol, &c, it may be procured in the 
greatest purity. 
Cetrarine and its combinations, analogous to salts, precipi- 
tate the salts of iron, of a red color; those of copper, green; 
those of lead and silver, white. Its alcoholic solution is preci- 
pitated, more or less promptly, and more or less copiously, by 
arsenious acid, the salts of cobalt, nickel, zinc, cadmium, the 
protoxides of mercury, and of manganese. The salts of the 
deutoxide of mercury, the cyanide, and the cyanide of potas- 
sium, &c, have no sensible action upon it. It precipitates 
black the solution of gold, and lilac that of platinum, but only 
at the end of some hours. 
It produces no change in alcoholic solutions of the organic 
bases. Dried in the apparatus of M. Liebig, the combination 
of cetrarine with oxide of lead, free from carbonic acid, does 
not lose any weight; cetrarine is, therefore, anhydrous. 
0.166 grains of the combination of cetrarine and the oxide 
of silver, perfectly dry, gave 0.0160 of silver, 0.200 grains 
gave 0.0194; this combination, therefore, consists of — 
Expt. 1. Expt. 2. 
1 Arg. 1451.607 10.3888 10.3516 10.4176 
1 Cetr. 12521.073 89.6112 89.6484 89.5824 
1 Arg. cetr. 13972.680 100. 100. 100. 
According to these numbers the capacity of saturation is 
but 0.798, and if the combination of cetrarine with oxide of 
silver can in fact be considered as neutral, this substance will 
VOL. IV. — NO. i. 8 
