MOLECULAR CONSTITUTION OF THE ORGANIC BASES. 
359 
version is completed. While engaged in these experiments, I found that the result 
intended may be obtained almost instantaneously by substituting the iodide for the 
bromide of ethyl; and as this observation was immediately followed by a perfect 
elucidation of the whole question, I have scarcely returned again to the use of the 
bromide. 
On adding perfectly anhydrous iodide of ethyl to triethylamine dried over hydrate 
of potassa, the mixture becomes slightly turbid, heat being evolved at the same time. 
At the common temperature the action goes on very gradually, and after the lapse of 
several days, the mixture is converted into a solid mass. On the other hand, if the 
mixture be exposed for a minute or two to the temperature of boiling water, a very 
powerful reaction ensues ; the liquid remains, even after the removal of the source 
of heat, for some time in a state of lively ebullition, and solidifies after cooling, into 
a hard mass of crystals, which is snow-white or of a yellowish tint, according as 
either the triethylamine or the iodide of ethyl has been in excess. To avoid losing 
iodide of ethyl, and especially triethylamine, which is the result of a long series of 
troublesome and expensive processes, I have usually performed the reaction in strong 
glass tubes of between three and four feet in length, which were sealed before the 
blowpipe after the substances had been introduced. 
The crystalline mass produced in this reaction readily dissolves even in cold water. 
If the iodide was in excess this substance separates in heavy oily globules, which 
may be readily separated and recovered by distillation, and the solution is inodorous, 
and either neutral or very slightly acid ; in the latter case it has always a marked 
yellowish tint. On the other hand, if the base was in excess, the solution of the 
crystals was colourless and alkaline ; the alkaline reaction disappears however on ebul- 
lition, triethylamine being disengaged. The crystals are likewise soluble in alcohol, 
but almost insoluble in ether. 
The puriiication of the crystals is not attended with any difficulties ; it is in fact 
sufficient to dissolve them in cold water and to allow the solution to evaporate spon- 
taneously, when beautiful well-defined white crystals of considerable size are depo- 
sited, which may be easily separated by mechanical means, from small quantities of 
a reddish iodine-compound, which is sometimes formed by the action of the air. This 
latter substance is formed in much larger quantity at higher temperatures, wherefore 
it is advisable to avoid the use of boiling water in the purification. 
The crystals are anhydrous ; when exposed to the temperature of boiling water 
they exhibit no change in weight. When submitted to analysis they gave the follow- 
ing results : — 
I. 0‘4385 grm. of substance gave 0'6015 grm. of carbonic acid and 0*3040 grm. of 
water. 
II. 0*5538 grm. of substance gave 0*5050 grm. of iodide of silver. 
III. 0*5205 grm. of substance gave 0*4752 grm. of iodide of silver. 
IV. 0*5000 grm. of substance gave 0*4552 grm. of iodide of silver. 
3 A 2 
