This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol1", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
This is a new preparation of opium, introduced into our Pharmacopoeia at the late revision. It is made by macerating opium in water so as thoroughly to exhaust it of all matter soluble in that liquid; evaporating the infusion thus obtained to a certain measure, and agitating the residue thoroughly with ether; then pouring off the ether which sepa-rates on standing, and completely evaporating what remains, of it; finally, adding first water, and subsequently, after filtration, half of its measure of alcohol. It will be seen that, in this process, all substances in opium soluble in alcohol and not in water, some of which are believed to be noxious, are got rid of; while, by washing with ether, the narcotina and the offensive odorous principle are separated, and alcohol is added at the end sufficient for its preservation. It is an excellent preparation, and, if properly made, may be relied on for whatever advantages may be possessed by certain empirical elixirs, which have acquired popularity through the want of an officinal preparation like this. It may be used for all the purposes for which laudanum is prescribed, and in the same dose; and may be preferred to it, whenever found not to agree with the patient, in consequence of constitutional peculiarities.