212 
DR. GLADSTONE ON CIRCUMSTANCES MODIFYING 
restored again on the addition of ammonia*. It occurred to me, that though ammonia 
is capable of displacing sesculine from its combinations, sesculine ought to be able 
to decompose more or less the ammoniacal salt. Accordingly a large quantity of 
hydrochlorate of ammonia was added to a solution of horse-chestnut bark, and it 
certainly did reduce the blue more than a similar amount of water did in a compa- 
rative experiment, while the addition of ammonia to the mixture revived it. 
Tincture of stramonium owes its fluorescent properties also to a free alkaloid, and 
the blue is similarly destroyed by hydrochloric acid, and restored by ammonia. The 
action of hydrochlorate of ammonia was tried in like manner with this tincture, and 
it seemed to give the same results as in the case of horse-chestnut bark ; but they 
were more decided. 
Compound Ethers. 
Compound ethers may be regarded as organic salts in which certain compound 
radicles take the place of metals, and it is to be expected that' they will follow the 
same general laws as the binary compounds that have been previously examined. 
Their insolubility in water precludes the use of aqueous solutions of the substances 
intended to act upon them, but alcohol affords a convenient medium for the reaction, 
and when this is employed, results are obtained which are perfectly analogous to 
those already described in the case of different metallic salts. The following expe- 
riment may be taken as an example. A large excess of oxalic acid was dissolved in 
alcohol along with acetic ether, warmed, and allowed to stand for some hours. The 
mixture was then submitted to gentle distillation, and there passed over acetic ether 
mixed with alcohol and with oxalic ether, as was proved by decomposing the distillate 
by hydrate of potash, and testing the resulting salt in the usual manner, when both 
acids were detected in considerable quantity. The oxalic acid had therefore displaced 
a certain amount of acetic acid ; but though it existed in such large excess that it 
began to crystallize out, it had not displaced the whole. 
I have not examined these reactions among compound ethers to any considerable 
extent, nor have I performed any of the experiments quantitatively, because I was 
aware that Professor Williamson (to whom this branch of the subject more parti- 
cularly belongs) has been pursuing some investigations in the same direction. 
GENERAL INFERENCES FROM THE PRECEDING EXPERIMENTS. 
The concurrent testimony of the diversified experiments here detailed is in favour 
of the view, that when two binary compounds are mixed in solution, there ensues a 
partition of the two electro-positive between the two electro-negative elements, 
according to certain proportions regulated both by the difference of strength in the 
affinities, and by the relative quantities of the different bodies. The reverse of this 
does indeed appear at first sight to be the case in certain instances, as for instance, 
* See the paper of Stokes already referred to. 
