on Hoffman's anodyne liquor. 
215 
cipe gives no direction to isolate the oil of wine before measur- 
ing it, which is perhaps less necessary, as the ethereal part of 
the distillate is removed previously to the production of the oil 
which is found in the receiver in globules, and not in solution. 
The process now adopted by the manufacturers in this city 
avoids the isolation of the oil of wine, and from the nature of 
the conditions the product is liable to vary in the proportions of 
its ingredients, not only in different laboratories, but at different 
operations in the same laboratory. In the preparation of ether 
it is usual in this city to push the process as far as possible, as 
Ions: as the residue is not so concentrated as to eliminate much 
permanent gas. In the rectification of this first crude product, 
the distillate is reserved as rectified ether as long as its specific 
gravity marks 54° Baume, or there about. By continuing the 
process the product is found to consist of ether, alcohol and 
water, impregnated with oil of wine. Every one who has made 
ether knows how very liable the product is to vary with an ill 
regulated heat ; on the one hand unaltered alcohol will pass over 
if the temperature is too low, whilst too great a heat, especially 
towards the last of the process, will favor the formation of oil 
of wine and sulphurous acid. This last distillate, therefore, will 
vary in composition, and it is from this that Hoffman's anodyne 
is made in some of the best of our laboratories. There is no 
known practicable method of ascertaining the per centage of heavy 
oil ofivine in this liquid. The means used by the manufacturer are 
founded on the sensible properties of an arbitrary standard spe- 
cimen of Hoffman's anodyne previously made, and on the degree 
of opalescence or milkiness it produces when added to a certain 
measure of water. This milkiness is occasioned by the oil of 
wine present ; but experience has shown that the degree of milki- 
ness is not strictly in proportion to the quantity of oil present, 
the relative proportion of ether and alcohol, and perhaps water 
present in the anodyne liquid has a marked influence on the phe- 
nomenon ; if too much alcohol, the milkiness is not produced, or 
but partially ; if too much ether, oily globules separate and float 
with but moderate opalescence. In converting his second ethereal 
distillate into commercial Hoffman's anodyne, the operator has 
to make several essays, sometimes adding water, sometimes alco- 
hol or ether, until the taste, the smell, and the opalescence agree, 
