CHINOLINE AND ITS HOMOLOGUES. 393 
ment be successful, the solution merely retains a slight blue tinge. This preci- 
pitate appears to be the new base, although probably in a very impure state. 
When first thrown down, it has a beautiful reddish-violet colour, like that of the 
crystallized sesquichloride of chromium. It may be washed with water on a 
filter, being sparingly soluble; it dissolves readily in alcohol, forming a fine crim- 
son fluid, which precipitates a spirituous solution of chloride of mercury. The 
base dissolves readily in hydrochloric acid, the solution giving a voluminous pre- 
cipitate with bichloride of platinum. The platinum salt, after well washing with 
water, was burnt for the percentage of metal, to ascertain whether its atomic 
weight was higher or lower than that of ethy]-chinoline. 
{ 2-081 grains of platinum salt gave 
492 ... platinum. 
212-2 157-0 
Atomic weight of new base. Atomic weight of ethyl-chinoline. 
The atomic weight which is derived from this experiment is so excessively 
high, that no simple relation is apparent between the red product and ethyl- 
- chinoline. The single platinum determination, although carefully made, is evi- 
dently insufficient to enable any speculation to be made as to the nature of the 
decomposition. 
It is known that most nitryl bases (those composed solely of the alcohol 
radicals being the chief exceptions) yield colours by the action of oxide of silver 
on the ammonium compounds formed with methyl, ethyl, and amyl, but I think 
none yet worked on yield such magnificent tints as those mentioned in this paper. 
The subject has another and much greater point of interest than the mere forma- 
tion of coloured reactions, however beautiful they may be, inasmuch as the care- 
ful following out of the decompositions on the large scale promises to assist us in 
4 acquiring a knowledge of the constitution of alkaloids of this class. I have there- 
_ fore promised myself to examine the matter more fully, when the other investi- 
gations with which I am now occupied are concluded. 
Action of Iodide of Amyl on Chinoline. 
Aydriodate of Amyl-Chinoline.—Iodide of amyl reacts with comparative slow- 
ness upon chinoline. It is necessary to keep the materials in a pressure-tube for 
some hours at 212° to effect combination. The iodide crystallizes from alcohol with 
_ extreme readiness, and when evaporated slowly upon flat surfaces presents under 
_ the lens very peculiar and beautiful forms. On one occasion, after dissolving the 
iodide in alcohol in a beaker, the fluid was poured into another vessel, and the 
solution remaining on the sides crystallized in the manner I have endeavoured to 
illustrate in the annexed sketch. The figure represents the forms about four 
times the natural size. 
VOL. XXI. PART III. 50 
