TESTS FOR IMPORTANT MEDICINAL PREPARATIONS. 567 
susceptible of easy practical discrimination by simple means, 
the writer is at present able to offer the following: 
Ether . — A strip of unsized paper, or a clean glass rod, 
dipped into the ether and allowed to dry for a moment or 
two, will by the odour it gives afford evidence of the less 
volatile impurities that it commonly contains. There usually 
remains a somewhat aromatic, slightly pungent odour, that 
is not hurtful in the more dilute ether used for common 
medicinal purposes, but the disagreeable oily odour often 
found is more objectionable, w r hi)st really good ether should 
leave no odour whatever. The ether used for inhalation 
should leave upon the sponge, paper, or rod, no foreign odour 
at all. 
The strength of ether is less easily ascertained except by 
a specific-gravity instrument. With a little practice, how- 
ever, with some good specimen for comparison, a very satis- 
factory estimate may be found by observing the slowness or 
rapidity with which any given specimen evaporates from the 
palm of the hand. Ether for inhalation should give off 
bubbles of vapour rapidly at the temperature of the palm of 
the hand. A thin test-tube, containing the specimen, should 
be grasped firmly for a minute or two, and then the ether 
should be stirred at the time of observation. The bubbles 
arise from the points of contact between the tube and 
stirrer. 
Compound spirit of ether — Hoffman's anodyne . — Two drops of 
officinal spirit stirred into a pint of water give to the mixture 
a distinct oily surface, and the peculiar fruity, aromatic odour 
of the heavy oil of wine, free from the odour of ether and 
alcohol. Sixty drops in the pint renders the water decidedly 
turbid. While, with four fluid drachms to the pint, a scanty 
precipitate of minute oil-globules occurs after a few minutes’ 
standing. The fruity, apple-like odour is characteristic of the 
chief anodyne ingredient, the oil of wine, and is entirely 
wanting in the ordinary commercial article. Without the 
oil of wine the preparation is a stimulant antispasmodic. 
With the oil it is a highly valuable anodyne antispasmodic, 
particularly adapted to nervous irritation and hysteria. The 
liquid universally sold as Hoffman’s anodyne is a residue of 
the ether-making process, containing varying proportions of 
ether and alcohol with a little etherole or light oil of wine, 
but in no single instance of the many examinations made by 
the writer, has any true heavy oil of wine been found in it 
Heavy oil of wine, from being expensive and somewhat diffi- 
cult to make, has finally been entirely omitted from the pre- 
paration, and is now hardly to be met with in commerce. 
