G22 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
[February 1,1871. 
believe that the difference in price would he any¬ 
thing worth regarding as an obstacle to that prac¬ 
tice ; but in making this suggestion it is neces¬ 
sary to particularize the kind of crystal to which I 
refer, for there are several kinds of crystallized or 
crystalline chloral preparations. That which I be¬ 
lieve to be the purest, presents commonly the appear¬ 
ance of ordinary alum broken into fragments about 
the size of grains of paradise (in one instance I have 
met with very definitely formed crystals resembling 
sulphate of potash) ; the fragments are perfectly 
transparent, free from powder, possessing very little 
odour, and when turned out upon the hand they feel 
dry and do not become moist by exposure. 
This appears to be the form in which chloral hy¬ 
drate is most definite and uniform, and, therefore, 
best suited for dispensing purposes, quite indepen¬ 
dently of its being obtained from any particular maker. 
But there are several other varieties of crystals : 
sometimes the preparation is in the form of minute 
acicular crystals, like chloride of ammonium ; some¬ 
times it has the appearance of chlorate of iiotash, and 
sometimes it is in definite needle-shaped crystals, 
like oxalate of ammonia. Very frequently these 
crystals are more or less moist in appearance, and 
on exposure this character becomes more marked. 
The definite needle-shaped crystals last mentioned 
are, I believe, characteristic of the alcoholate. I 
have only met with one sample of this kind in com¬ 
merce, and have not yet obtained a sufficient quantity 
of it for analysis. As regards the other acicular and 
tabular crystals, however, they appear to be decidedly 
inferior to that form of crystallized chloral hydrate 
described above, and they do not seem to be very 
much preferable to the cake. 
Still none of the samples give results at all ap¬ 
proximating to those which would be obtained from 
alcoholate, nor does it appear that any of the samples 
examined contained less than 87 per cent, of chloral 
hydrate. In the case of that sample which gave the 
lowest result, there was a copious separation of a 
flocculent liumus-like substance between the chloro¬ 
form and the supernatant liquid, and that obscured the 
true volume of the chloroform layer. The same deposit 
was found to some extent in testing other samples. 
According to the analysis made by Mr. Eugene 
De Haen, and referred to last week in the letter from 
Messrs. De Haen, the choral hydrate they make 
gives the following results :— 
Boiling- 
point. 
Chloroform 
Layer 
(after the List 
of Mr. Mason). 
Quantity of 
Chloroform pro¬ 
duced from 500 
grains of the 
Chloral com¬ 
pound byweight. 
General Re¬ 
marks. 
i 
Centigr. 
1)7° 
Grain- 
measures 
240 
353 grains, 
or 
71 per cent. 
A crystal¬ 
line cake 
(crystal) so¬ 
luble in wa¬ 
ter, ether, 
alcohol; in¬ 
soluble in 
chloroform, 
etc.; has all 
attributes of 
a really che¬ 
mically pure 
chloral-hy¬ 
drate. 
_ i 
Since writing the above Messrs. Domeier have 
forwarded a letter, which appears in the Correspon¬ 
dence columns, and the results of two analyses by 
Dr. Versmann, which are as follow :— 
Samples. 
Boiling-point. 
Chloro¬ 
form 
layers, 
grain- 
measures. 
Quantity of 
Chloroform 
from 500 
grains hydrate 
by weight. 
Corresponding 
to percentage 
of pure 
chloral hy¬ 
drate. 
General Remarks. 
Crystals . . 
96° to 97° C. 
235 gl’S. 
35 7’8 grs. 
or 
70'3 p. c. 
97 43 p. c. 
Fine white crystals, slightly deliques¬ 
cent, dissolved very freely in water, dis¬ 
solves in alcohol, ether, etc., not quite 
insoluble in chloroform. 
Cake . . . 
96° to 97° C. 
232 gl’S. 
347-3 gi-s. 
or 
69’4 p. c. 
9G - 20 p. c. 
White opaque cake, not quite dry, 
readily soluble in water, alcohol, ether, 
etc., not quite insoluble in chloroform. 
Both begin to solidify after having been 
melted at 49° C.; specific gravity of liquid 
at that temperature is 1-610. 
. samples are pure chloral hydrate, which have by exposure to air attracted some moisture, which 
is the cause of the deficiencies in the percentage. 
Aftei decomposition with ammonia and separation of chloroform, no crystals of iodoform could be ob¬ 
tained from the solution, proving the absence of any alcohol. 
In reference to Mr. Abraham’s remarks on the 
ammonia test as reported in the proceedings of the 
Liverpool Chemists Association, I may remark that 
caie must be taken to ensure completion of the re- 
action befoie reading off the volume of chloroform. 
Of com se the temperature to which the tubes have 
to be heated must be regulated by the nature of the 
pioduct. A temperature of 100° F. maintained for 
three or four hours is quite enough. Meanwhile, the 
tubes should be well shaken. If these precautions 
be not observed, probably very little chloroform may 
be produced, or it may happen that the chloroform- 
layer appears to be much larger than it ought to be. 
In such cases it will be found that after some hours 
rest, crystals separate from the chloroform. This 
latter circumstance is due to incomplete decomposi¬ 
tion of the chloral hydrate and its solution in the 
chloroform produced, apparently with increase of 
volume. On heating a tube in this condition, the 
recommencement of the reaction will be at once ap¬ 
parent, and after cooling, the chloroform layer wi U 
be found reduced to its true volume. 
