This section is from the book "Botanic Drugs Their Materia Medica, Pharmacology and Therapeutics", by Thomas S. Blair. Also available from Amazon: Botanic Drugs, Their Materia Medica, Pharmacology and Therapeutics.
The Eighth United States Pharmacopeia lists 10 alkaloids, 26 alkaloidal salts, 14 preparations of alkaloids, 2 basic substances, 2 preparations of basic substances, 3 neutral principles, 7 oleo-resins, 3 proximate resins, 2 glucosides, and 2 proximate gum resins, a total of 71. Omitting salts and preparations, there are about 20 important agents. "New and Nonofficial Remedies" adds a few new products, some of which may prove to be of importance.
"Merck's Manual" lists these and 33 uncertain concentrations and resinoids, and "Merck's Index" adds a number more of so-called proximates. There have been 92 alleged proximates broken out of digitalis alone; and the sum total of so-called proximates mentioned in the dispensatories total several hundred.
This mere statement of facts will suffice to make it clear that there are many uncertain alkaloids and other proximates, even as there are uncertain crude botanic drugs; there are "proximates" of very unstable and varying composition; there is no greater certainty and definiteness in proximates as a class than there is in "galenicals" as a class; and, finally, there is a limited list of proximates of so useful and definite a place that every physician should use them when indicated.
Taking as a guide the experience of the profession at large, there are few alkaloids and proximates of greater importance than the parent drugs from which they are derived. It is fair to say that quinine is more important than is cinchona, cocaine than coca, and the resin of podophyllum than podophyllum itself. Perhaps aloin, atropine, caffeine, hyoscine, hyoscyamine, morphine, pilocarpine, scopolamine, strophanthin, and strychnine may be classed as approximating in value the plants from which they are derived, and even this is largely a matter of opinion. At all events, when we start in to argue for the importance of the proximates as against their parent plants, we are limited to a rather short list of proximates. There are many relatively valuable proximates. Apomorphine hydrochloride is certainly in this class, as are others; but it all comes down to practical questions of usage. Certainly certain emergencies demand the prompt hypodermatic use of apomorphine, atropine, morphine, and strychnine on occasion; but it is equally true that, in the ordinary routine of practice, the use of the proximates may be readily overdone.