MOLECULAR CONSTITUTION OF THE ORGANIC BASES. 
361 
The eagerness with which I submitted this question to the test of experiment may 
be readily imagined. On adding potassa to a solution of the iodine-compound in 
water, the liquid solidified at once into a crystalline mass, which I took of course for 
the base existing in the iodide ; analysis however soon showed that the substance 
thus precipitated is nothing but the iodide itself, which is less soluble in an alkaline 
solution than in pure water. In fact, Analysis IV. was made with a specimen which 
had thus been treated with potassa. The iodide was now distilled with a very 
concentrated solution of potassa for several hours ; but during this time nothing but 
pure water passed over; the solution in the retort solidified on cooling to crystals of 
the unchanged iodide. When the solution of the iodide in potassa had become very 
concentrated, it separated into two layers, an aqueous one and an oily one, which 
floated on the surface. But even now no decomposition had been induced, the oily 
stratum solidifying on cooling into a crystalline cake of iodide perfectly unaltered. 
It was only when the liquid was evaporated to dryness that a change took place ; but 
then the change was no longer due to the action of the potassa, but to the influence 
of heat, and in no way differed from the decomposition which the crystals undergo 
when heated alone. 
The deportment with potassa of the new iodine- compound altogether precludes the 
idea of considering it as an analogue of the hydriodides of ethylamine, diethylamine, 
and triethylamine, all of which are readily decomposed under the influence of the 
alkalies. 
However, the iodine, though it cannot be eliminated from the crystals by the 
alkalies, may be separated with the greatest facility by silver-salts ; in fact, the nitrate, 
the sulphate, the oxide of silver, behave with the iodine-compound exactly as with 
iodide of potassium or sodium. On adding nitrate of silver to a solution of the iodide, 
iodide of silver is at once precipitated and a nitrate remains in solution, which on 
evaporation crystallizes in deliquescent needles. With sulphate of silver, a perfectly 
similar change takes place, an analogous sulphate remaining in solution. During 
these interchanges the liquids remain perfectly neutral. If the solution of the iodide 
be digested with freshly precipitated protoxide of silver, the solution at once assumes 
a powerfully alkaline reaction, iodide of silver being formed : the same effect is pro- 
duced by the action of caustic baryta upon the sulphate, sulphate of baryta being 
precipitated. These reactions, when viewed collectively, exhibit a striking analogy 
between the new iodide and the metallic iodides, especially those of the alkali-metals. 
In fact the molecular group combined with iodine, in the compound under examina- 
tion, behaves like sodium or potassium ; it is a true organic metal in all its bearings. 
For this metal I propose, on the ground of its formation and composition, the name 
Tetrethylammonium (rerpa), which implies that it is built up by the intimate union 
of nitrogen with four equivalents of the hypothetical hydrocarbon called ethyl, and 
that it may be viewed as ammonium, in which the whole of the hydrogen is replaced 
by an equivalent proportion of the above hydrocarbon. 
