308 
ANAESTHETIC AGENTS. 
It dissolves iodine, sulphur, and phosphorus. When warmed 
and acted on by oxidizing agents, such as platinum black, it 
is converted into valerianic acid , according to Cahours, which 
bears the same relation to amylic alcohol that acetic acid 
does to ordinary alcohol, or formic acid to wood-spirit. 
Amilen, according to Dr. Snow, may be obtained by dis- 
tilling this fusel-oil, or amylic alcohol, with chloride of zinc. 
Cahours, a French chemist, discovered it some years ago, 
and, it appears, procured it from the potato, or fusel-oil, by 
distillation with anhydrous phosphoric acid. It is a colour- 
less, oily, volatile liquid, lighter than water, and boils at 320°, 
or thereabouts. It is one of the hydro-carbons, isomeric, 
with olefiant gas and etherine, but the density of its vapour 
is five times as great. Its composition is C 10 H 10 ’, its com- 
bining number or equivalent, 70. 
The advantages derived from the use of this agent in the 
human subject are, that nausea and headache are not so 
severe after it as chloroform, nor is sickness produced by it. 
These reasons, however, will not weigh with us, and when it 
is borne in mind that a larger quantity of it is required than 
chloroform, although less than sulphuric ether, it becomes a 
question if it will ever be employed for the lower animals. 
Besides which it is also more expensive. 
There have not been wanting those who have condemned 
the inhalation of hypnotic agents altogether, on account of 
the many fatal cases that have resulted from their exhibition. 
Among these is Dr. Arnott, who contends that all that can 
be desired, or is wanted, may be obtained by the benumbing 
influence of cold, since the seat of pain in all operations is the 
skin. For this purpose he forms a frigonfic mixture, by 
mixing together two parts of finely pounded ice and one 
part of salt, which he encloses in a silken- tissue bag (a 
bladder would be a convenient receptacle for the lower 
animals), and this he lays upon the part to be operated 
on. In a few minutes the skin will become blanched and 
perfectly insensible to pricks or incisions with a knife, while 
the patient retains complete consciousness. It scarcely need 
be added, that no injurious results can be anticipated. The 
insensibility lasts for several minutes, and the parts quickly 
resume their normal condition. Cold, by some writers, is 
considered the only direct sedative we have, yet Shakespeare 
says that — 
“ It doth glow the cheek that it doth cool.” 
This, perhaps, may be explained by what Dr. Arnott states 
when referring to the effects of benumbing cold : “ The skin 
and adjacent textures immediately become perfectly in- 
