M. C. Lea—Silwer Salis and Coloring Matters. 53 
A Il.—On Combinations of Silver Chloride, Bromide and 
RT. X 
Lodide with Coloring Matters ; by M. Carry Lna, Philadelphia. 
has prevented the continuation of the investigation. It is still 
Sie and the leading facts only are mentioned here to 
xe date. 
_Not all coloring matters are capable of uniting with the 
silver salts, but the number of those that do so unite is consid- 
erable. hat is curious and tends to show that the combina- 
ton is intimate is that the color assumed by the silver salt is 
not always that of the dye, but may differ from it considerably. 
Also the three silver salts may be differently colored by one 
and the same coloring matter. 
More frequently, however, coloring matters impart their 
own shade or something approaching to it; thus, silver bro- 
mide precipitated in presence of excess of silver nitrate takes 
from aniline purple a strong purplé color; from cardinal red a 
bright flesh or salmon color; from napthaline yellow a light 
Yellow color; from eosin a brilliant pinkish or salmon, and so on. 
_Vifferent specimens of the same color gave sometimes quite 
different results; thus silver bromide precipitated in presence 
of silver nitrate was dyed by one specimen of methyl green to 
a bluish green. Another specimen of the same color obtained 
om a different source colored the same silver salt a deep 
ages shade. Silver iodide showed the same difference. 
* British Journal of Photography, 1868, 210, 506; 1870, 145, ete. 
