ALCOHOL AS A TEST FOE. CROTON OIL. 
385 
companied also by one of croton oil expressed from seed in this country about 
fourteen years since. The sample of imported oil was marked u ex Earl of 
Auckland v. Rotterdam in transit from Batavia.” 
Experiment 2.—Ten volumes of imported oil were mixed, as before, with ten 
volumes of alcohol, and briskly agitated. It soon separated, and was then 
again shaken and gently warmed ; perfect solution followed, and the tube was 
set aside. In a few hours the contents had separated into two layers, the oil 
measuring 11*5 volumes, and the alcohol 8'5 ; also coloured, from solution of 
part of the oil. This result shows a slight increase on that obtained by Dr. 
Pereira from East Indian croton oil, which was, from experiment No. 2, 10*94 
volumes of oil, after separation. 
Experiment 3.—Ten volumes of the old English-expressed oil were mixed 
with ten volumes of alcohol, as before, only as they seemed to unite immediately 
no agitation was required ; the mixture was very turbid, but exhibited no signs 
of separation. On being warmed, it became transparent and remained per¬ 
manently dissolved. Here then was a case corresponding exactly with the 
results published by Dr. Pereira in experiment 6. This old oil was very thick, 
and when the cold weather commenced became slightly crystallized. 
In consequence of this result, I procured a sample of croton oil from Messrs. 
Hodgkinson, Tonge, and Co., and also another specimen of the imported oil. Ex¬ 
periment 4.—Ten volumes of croton oil (Messrs. Hodgkinson, Tonge, & Co.) + 
ten volumes of alcohol were gently mixed, and then agitated briskly ; separation 
soon occurred; the mixture was then warmed, when it formed a clear solution, 
which, by standing a few hours, separated into 9 volumes of oil and 11 of 
alcohol, the latter being much coloured, as in experiment 1. 
Experiment 5.—Ten volumes of imported oil (specimen No. 2) -f- ten volumes 
of alcohol treated as before, yielded the same results as experiment 2. 
In consequence of the alcohol in all these experiments becoming nearly as 
dark-coloured as the oil itself, the whole were put aside in a bottle for future 
experiment. When the result of experiment 3 was poured in, to my great 
surprise, the results from experiments Nos. 1 and 2 instantly formed a clear 
solution, and this also occurred on the addition of the separated materials 
from numbers 4 and 5. So that we have here the presence of 10 volumes of old 
oil causing 40 volumes of croton oil (composed of 20 volumes of English-ex¬ 
pressed, and 20 volumes of imported oil) which would not dissolve in alcohol, 
to enter into perfect solution, and this without any application of warmth. I 
shall have occasion to refer to this again presently. 
From these results, I was induced to try the solvent action of rectified spirit 
upon some of the specimens of croton oil. Experiment 6.—Ten volumes of 
English-expressed oil -(- ten volumes of rectified spirit, sp. gr. 838, were mixed as 
before, and well shaken together, but without solution ; the mixture warmed, but 
still no evidence of solubility. Mechanical admixture only took place, and this 
was followed by rapid subsidence of the oil. 
Experiment 7.—Ten volumes of the English-expressed, fourteen-years-old oil, 
+ ten volumes of rectified spirit, were mixed together and did not separate ; 
though turbid, the solution appeared to be perfect on the following morning, 
however, it was found that it had divided into two strata. 
I have mentioned that these experiments were commenced in June, and the 
temperature of the air at that time was seldom below 70° Fahr. day or night. 
On the night of this last experiment, however, it was observed that the ther¬ 
mometer had fallen a few degrees lower. For the moment the separation of 
the oil was not attributed to the influence of this slight diminution of tempe¬ 
rature, and the experiment was therefore repeated exactly as before; no solu¬ 
tion, however, could be obtained by simple admixture, and when this was 
effected by a gentle heat, separation took place in a few hours by standing It 
