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THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. [November 25, 1871. 
times the quantity, a mixture of equal volumes of 
amylic alcohol and H N 0 3 , the retort being con¬ 
nected with an efficient condenser, a gentle and 
very gradually increasing heat is applied; after 
rising to a certain temperature the source of heat is 
withdrawn and the reaction allowed to go on hy 
itself. Considerable frothing and violent action 
take place if the heat has been too long applied; 
the thermometer inserted in the tubulus of the re¬ 
tort rapidly rises, and the product produced is col¬ 
lected until the temperature rises to 100° C., after 
which the receiver is changed, as the product then 
becomes too impure to be of any use, containing as 
it does nitrate of amyl and ethyl-amylic ether; this 
may be readily distinguished by the change there is 
in the odour of the distillate. The product which 
was collected before the temperature reached 100° C., 
is now treated with a solution of NaHO, which re¬ 
moves and fixes both the free H N 0 3 with which 
it is sure to be contaminated, and also the HCN, 
formed during the decomposition of the amylic 
alcohol by the nitrous gas; in this reaction, omitting 
secondary decompositions, the H N 0 3 is reduced to 
H N 0 2 , which attacks the amylic alcohol forming 
nitrite of amyl. Of course this reaction is nothing 
like perfect, or we should have the pure nitrite 
without further trouble; part of the nitric acid 
escapes decomposition entirely, hence the presence 
of nitrate in it. HCN, also, is formed, and may be 
detected in the alkaline solution used for washing 
the impure product, in the form of KCN or NaCN, 
as the case may be; it may also be detected in the 
product itself, by means of a drop of Ag N 0 3 placed 
in the centre of a watch-glass and inverted over an¬ 
other glass containg a small quantity of the impure 
nitrite; AgCN is produced in the form of a white 
him on the surface of the drop. The washed pro¬ 
duct is separated by decantation or by means of a 
pipette and introduced into a clean retort and again 
slowly distilled. That portion which comes over 
before the temperature reaches 90° C., contains the 
amylic aldehyd; this is set aside and a fresh re¬ 
ceiver placed. That collected between 98° and 100° C., 
consists for the most part of nitrite of amyl. After 
the temperature has risen to 100° C. the distillation 
is stopped ; the retort will contain the ethyl-amylic 
ether, whose boiling-point is above 100° C. The 
yield by this process is very small, and it is in many 
respects inconvenient. Another process for pre¬ 
paring this substance is given by Nalder, which he 
says readily yields the pure nitrite, but the merits of 
which I am unable to state, having never had expe¬ 
rience with it; it consist in distilling amylo-sulphate 
of potash with nitrate of potash. Judging from ana¬ 
logy, if this process yields pure nitrite of amyl, it 
ought to he a very efficient one for the preparation of 
nitrite of ethyl, and, consequently, for spirit of nitre, 
a good process for which is still a desideratum; of 
course, in the latter, it would be necessary to use ethyl- 
sulphate of potash instead of the amyl compound. I 
am not prepared at present to state what difficulties 
there may be in the way of preparing the amyl-sul¬ 
phate of potash; the ethyl compound is not difficult to 
prepare, and a process for it may be found in most 
text-books on chemistry. 
Tiie process hy which I have been in the habit of 
preparing nitrite of amyl, and of which I now in¬ 
tend giving you a description, is one which I think 
will be found convenient for its preparation on a 
small scale, and of sufficient purity for medicinal 
use. I do not claim any originality for it, as it is 
probable that many may have thought of it although 
not put it into practice. So long ago as July last 
year, while making spirit of nitrous ether by the 
Pharmacopoeia process, the idea occurred to me 
that, with some modification, this might be made a 
convenient one for the preparation of nitrite of 
amyl. A demand for the latter arising just then, I 
put it into practice. In Mr. Maisch’s paper in the 
April number of the Journal for this year, he states 
that the same idea occurred to him, but that he 
found it not to answer, and this I think may be 
easily accounted for. The process for spirit of nitrous 
ether, as you are all aware, consists in distilling, at 
a certain temperature, a mixture of rectified spirit, 
sulphuric and nitric acids in certain proportion, and 
copper wire; the distillate consists mainly of a mixture 
of nitrite of ethyl and etliylic alcohol. Now, by substi¬ 
tuting amyl alcohol for the rectified spirit in this pro¬ 
cess, you get nitrite of amyl among other products ; 
but Mr. Maisch appears to have overlooked one fact, 
viz. that rectified spirit contains 16 per cent, of 
water, and that the amylic alcohol he used was 
nearly anhydrous. He states that the amylic alcohol, 
i. e. the purified substance, was mixed with sulphuric 
acid, the mixture introduced into a retort, together 
with some copper wire, and, after cooling, H N 0 3 
was added. In a very few moments the evolution 
of gas was observed , the liquid became hot without 
the external application of heat; and the reaction 
very rapidly increased to such a violence that the 
entire charge was lost, it being impossible to con¬ 
dense any of the vapours in a Liebig’s condenser, or 
to retain much of the liquid forced over into the re¬ 
ceiver. I may add, that I have repeated this expe¬ 
riment with exactly the same results ; nearly the 
whole charge was forced over into the receiver, and, 
while there, the action again commenced, and in¬ 
creased to such violence that I have no doubt it would 
have forced itself back into the retort again if their 
mutual positions had been favourable. As it was, I 
was obliged to introduce it to the open air, for the 
whole house became filled with the vapour, and 
every one who respired it became suddenly red in 
the face. Upon one of my assistants it had a very 
remarkable effect; it seemed to affect the muscles at 
the back part of the neck, and drew the head back¬ 
wards, but this soon passed off. I should quite 
expect that the reaction would be just as violent in 
making spirit of nitrous ether, if we used anhydrous 
alcohol instead of 84 per cent, as ordered. In pre¬ 
paring the nitrite of amyl by the process I employ, 
it is of the utmost importance that the amylic alco¬ 
hol be as pure as possible. Amylic alcohol, as you 
all know, is formed during the fermentation of pota¬ 
toes, rye, barley and the marc of grapes ; and when 
these are distilled it communicates a very pungent, 
and to many repulsive, odour and taste to the spirits. 
It is considerably less volatile than either ordinary 
alcohol or water, having a boiling-point, when pure, 
of 182° C.; in consequence of this property, it accu¬ 
mulates in the last portions of the liquids that are 
distilled. Its name is derived from amyl urn, starch, 
—this being the most abundant constituent 6f pota¬ 
toes. Liebig states that amylic alcohol is formed 
principally in the fermentation of alkaline oi* neutral 
liquids, and its production in the potato mash may be 
prevented in great measure by adding crude tartar 
to the fermenting liquid. Its formation never occurs 
in acidulous fermenting liquors which contain tar- 
