November 25,1871.] THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
423 
taric, racemic, or citric acids. The addition of hops 
to the liquid has a similar effect in checking the de¬ 
velopment of amylic alcohol, or fusel oil, as it is 
generally termed. It is, when pure, a colourless 
limpid liquid, of a penetrating and disagreeable 
odour, exciting headache and coughing when its 
vapour is inhaled. It is sparingly soluble in water, 
though it mixes in all proportions with alcohol, 
ether and essential oils. It is not easily inflam¬ 
mable, but burns with difficulty, giving a bluish 
flame. Its specific gravity, when pure, is '818, and 
boiling-point 132° C. Amyl alcohol is not acted 
upon by the atmosphere, except it be in a very thin 
layer, or under the influence of spongy platinum, 
when it is oxidized into valeric acid, C 3 H 10 O 2 , which 
acid bears the same relation to amylic alcohol that 
acetic acid, C 2 H 4 0 2 , does to ordinary alcohol. Fusel 
oil, as met with in commerce, is usually a clear 
yellowish liquid, with a peculiar penetrating odour, 
varying, of course, with the substance from which it 
has been produced. It has a specific gravity of 
from ’810 to ‘850, and is largely contaminated with 
the lower alcohols of this series ; so far as my expe¬ 
rience goes, it is only about half pure amyl alcohol. 
As I have before stated, it is of the utmost impor¬ 
tance, in the preparation of nitrite of amyl, that the 
amylic alcohol be as pure as possible, for it is much 
easier to purify this than to purify the nitrite pro¬ 
duced from it in its impure state. For this purpose, 
the best process is first to agitate the fusel oil with 
about an equal bulk of a strong solution of chloride 
of sodium; this usually reduces its bulk about 10 
or 20 per cent., and also considerably lowers the 
specific gravity. This washed product is separated 
and introduced into a retort furnished with a ther¬ 
mometer ; that portion of the distillate which passes 
over before the temperature reaches 125° C. consists 
mainly of the lower alcohols of this series, and whose 
boiling-points are below that of amylic alcohol, for 
the boiling-point rises in proportion as the compound 
is richer in carbon. The distillate collected between 
125° C. and 140° C. is collected apart, and redistilled 
until it has a boiling-point near 132° C.; this may 
then be considered pure enough for our purpose. 
This is then introduced into a glass retort contain¬ 
ing some copper wire, and furnished with a safety 
tube, and one-tentli its bulk of H 2 S0 4 added. The 
same quantity of H N 0 3 , diluted with an equal 
volume of water, is next put in, and a very gentle 
heat applied until the temperature reaches about 
65° C., when the reaction will commence and pro¬ 
ceed in a perfectly manageable manner, until a bulk 
about equal to double the quantity of H N 0 3 added 
collects in the receiver, the temperature in the mean¬ 
time rises to about 98° C. The reaction ceases very 
quickly, as in the case of spirit of nitrous ether. 
The temperature having fallen somewhat, another 
portion of H N 0 3 , equal in bulk to the first, is added, 
and this process of successive additions of the acid 
continued until nearly the whole of the amylic alco¬ 
hol is exhausted, which may be known by the dense 
red fumes evolved from the retort. The distilled 
product exceeds in bulk the amylic alcohol used, 
and is the impure nitrite of amyl. This is washed 
with solution of Na H O to remove the H C N and other 
free acids present, and rectified over fused K 2 C 0 3 to 
get rid of moisture. The portion which distils between 
95° and 100° C. is collected as nitrite of amyl, suffi¬ 
ciently pure for medicinal use. 
It has several times been stated that nitrite of 
amyl produces violent headache, and also coughing 
and irritation of the larynx; this, I think, must be 
due to its insufficient purification. The presence of 
H C N and undecomposed amylic alcohol would, I 
think, account for this; no such effect was produced 
on myself with the purified nitrite. Mr. Umney has 
shown, in an article in the Pharmaceutical Journal 
of November, 1870, that the samples then met with 
were very impure. 
VESICATING INSECTS. 
BY M. C. COOKE, M.A. 
( Continued from page 384.) 
Assam Blister Fly, Lytta assamensis, Water.; 
Lytta tibialis , Water. 
Probably forms of the same 
species. Cantharis assamensis, 
and G. tibialis, C. Waterhouse 
in Trans. Exit. Soc. Loud. 1871, 
p. 407. 
This species most nearly re¬ 
sembles G. rufieeps of Illiger, 
but is distinguished from it by 
the narrow margin of white 
pubescence to the elytra, and 
by the broad hairy anterior tibia 
in the male. 
Male.—The head is reddish-yellow, and (with the 
exception of a smooth spot at the base of each an¬ 
tenna) somewhat thickly, and not very strongly 
punctured ; the anterior margin of the clypeus is 
fuscous, as are the labrum and other parts of the 
mouth. The antennae are filiform; the third to sixth 
joints each notched for the reception of the follow¬ 
ing joint ; the third joint is about equal in length to 
the fourth and fifth joints together; the fourth, fifth, 
and sixth are rather short, nearly equal in length; 
the seventh to eleventh gradually increasing. The 
thorax is subquadrate (abruptly contracted in front), 
thickly, evenly, and distinctly, but not very strongly 
punctured; there is a slight impression on either 
side at the front, and a deep central fovea at the 
posterior margin. The elytra are scarcely broader 
at the apex than at the base, each rounded at the 
apex; the extreme margin and the suture fringed 
with white pubescence. The anterior tibiee are 
broader towards the apex, thickly set with long 
black hair on the outer side; the inner side of the 
fore femora and tibiae are clothed with yellowish 
pubescence. 
The female of G. tibialis have the third to sixth 
joints of the antennae not so strongly notched at the 
apex, the head without the smooth spot at the base 
of the antennae and the fore tibiae without long pu¬ 
bescence. The species which I have named G. 
tibialis (Trans. Ent. Soc. Bond. 1871) differs from 
G. assamensis in having the head less thickly punc¬ 
tured, and in having the mesothoracic epimera 
clothed with white pubescence.— C. IF. 
This species is found in Assam, where it is em¬ 
ployed as a vesicant, and probably also in Upper 
Bengal. The two forms or species are collected 
together indiscriminately. 
Nepal Blister Fly, Lytta Nepalensis, Hope; 
black, head rufous, antennae filiform, tibiae not 
hairy behind, elytra bi’oader towards the apex.— 
j Epicauta nepalensis, Hope, Gray’s Zool. Misc. p. 32. 
Fig. 8 .—Lytta 
assamensis. 
