PREPARATION OP THE VALERIANATE OP ZINC. 299 
Under these circumstances, a review of what has been 
published relating to the valerianate of zinc will undoubted- 
ly interest many of our readers. Valerianic acid, discovered 
by Planche, was isolated by Grote, and was investigated 
by Penz. It pre-exists in the root of valerian, but it may 
likewise be readily produced by acting with caustic potash 
on potato fusel oil. It is a volatile fat acid, colorless, soluble 
in every proportion in alcohol and aether, and soluble in 
about 30 times its weight of water. To obtain it, ; the vale- 
rian root is distilled until the product has no longer an acid 
reaction ; the essential oil which floats on the surface of the 
distilled water is separated, and the acid which it retains 
removed by shaking it with solution of caustic potash ; the 
distilled water is saturated with carbonate of potash, the 
liquids mixed, and then evaporated to dryness at a very 
gentle heat ; the residue, introduced into a retort and dis- 
tilled with a suitable proportion of dilute sulphuric acid, 
affords a saturated aqueous solution of valerianic acid, on 
which some pure valerianic acid floats. Two pounds of 
valerian root afford about 2 grms. of acid. 
To convert it into valerianate of zinc, it is saturated with 
the carbonate, or still better with perfectly pure oxide of 
zinc recently precipitated. The action is assisted by heat, 
the hot solution filtered and allowed to crystallize on a 
gently heated sand-bath. The crystals form light nacreous 
laminae of a brilliant white colour. According to M. Duclos, 
cold water dissolves one-fiftieth of its weight and boiling 
water one-fortieth. It is scarcely soluble in sether, but 100 
parts of boiling alcohol dissolve 6 parts. 
Valerianate of zinc was recommended as an antispasmo- 
dic, and the experiments of Dr. Devay were undertaken to 
determine its value as such. The results which he obtained 
have been remarkable from the quickness and completeness 
of the cures. The physiological effects are scarcely more 
decided than those of the valerian or of the zinc taken 
separately. A dose of 2 \ grs., which is sufficient to subdue 
