S 86 
ALCOHOL AS A TEST FOR CROTON OIL. 
was then found that as long as the temperature of the room was above 70°, 
the oil remained permanently dissolved, but that as soon as the thermometer 
had sunk three or four degrees lower, separation rapidly took place. So also 
with the mixed results of experiments 1, 2, 3, 4 and 5, as long as the tempera¬ 
ture was at 68°, or above that, so long the solutiou was perfect; but below 
that point, namely at 66°, separation gradually occurred. In consequence of 
these interferences from the effects of a few degrees differences of heat, 1 resolved 
to repeat these experiments when the temperature of the atmosphere was lower 
and more equable. 
November, 1864. Experiment 9.—Ten volumes of English-expressed croton 
oil (from Messrs. Hodgkinson and Tonge) + ten volumes of alcohol gave by agi¬ 
tation an emulsion which separated by standing into 8*3 measures of oil -f- 11 *7 
of alcohol. It was again agitated and warmed ; it readily dissolved, but in a few 
hours separated into 8*2 volumes of oil and 11 -8 of alcohol. The temperature 
of the air was about 50°. 
Experiment 10.—The imported oil from Batavia (No. 1) gave by cold admix¬ 
ture 10-2 oil -f- 9-8 alcohol; by warmth and subsequent deposit, 10*1 oil -j- 9 - 9 
alcohol. 
Experiment 11.—Imported oil (No. 2 sample) gave by agitation without heat 
10*2 oil -f- 9-8 alcohol; after heating and separation, 10*1 oil -f- 9*9 alcohol, being 
the same as experiment 10 on No. 1. 
Experiment 12.—-The specimen of old oil from Mr. Quincey yielded by agi¬ 
tation an opalescent or milky solution, which did not exhibit any signs of 
separation. 
Experiment 13.—The English expressed oil from Messrs. Horner, by cold ad¬ 
mixture and standing gave 9 of oil 11 alcohol; after solution by warmth and 
repose 8 9 oil -j- 11*1 alcohol. The temperature in this case was about 60°. 
I then made a few experiments with alcohol of *794 sp. gr., with the following 
results:— 
Experiment 14.—The imported oil from Batavia gave, by agitation, without 
heat, 9*3 volumes oil -j- 10*7 alcohol. After solution by warmth and subsequent 
deposit 9*4 oil -f- 10*6 alcohol. Temperature 56°. 
Experiment 15.—Horner’s English expressed oil, by cold agitation, yielded 8*8 
of oil + 11*2 alcohol. After dissolving by heat and standing, 8*7 oil -f- 11*3 
alcohol. 
Experiment 16.—The imported oil was again tried, but increasing the volumes 
acted upon to double their previous quantity, when it gave by the cold operation 
9*9 of oil + 10*1 of alcohol; after solution by heat and separation, 9*9 oil -j- 10*1 
alcohol. Temperature 58°. 
The results, from the experiments Nos. 14 and 16, were placed in the same 
bottle, and it was found that the oil entered into perfect solution at 75° Fahr. 
At 70° the solution became opalescent, but without any separation. But at 
67° a complete deposition of the oil took place. 
What conclusions now can we deduce from these results ? My own opinion 
is that freshly expressed croton oil, or rather, I should say, oil expressed from 
fresh seeds , either abroad or in this country, does not dissolve in alcohol having 
a specific gravity from *794 to *796, to a greater extent than twenty per cent, 
at the temperature of 50° ; but that if croton oil has undergone a chemical 
change, such as resinification or oxidation by time and exposure to the air, as in 
the old oil of the above experiments, or has been freshly expressed from seeds 
which have become changed in the same manner, then the oil is dissolved freely 
by the alcohol, as shown above and in the experiments of Dr. Pereira, which [ 
consider therefore must have been made with croton oil, freshly expressed it 
is true, but from seeds which had undergone a chemical change ; and this ac¬ 
cords with his own deductions from his experiments. At the same time I can- 
