RHUS — SUMAC. 121 



nmy l>o prrsorvcd iti i)ropor Mdlvciits for a grrat length of time. Tho 

 author himself Iiiis cxiu'vicncrd jjoisonoits cit'cctH from a tincture <:i li. 

 vcnciia/d i)re[)iir(Ml thirty _v( arH before, wliich was aiJiilied by way of exppin- 

 iiient. Peetiliar as the principle in, it finds its parallel in tho well-known 

 fact that only certain persons are Husccptiblo to its influence. This sus- 

 ceptibility nmy exist in all tlio members of a family, or in one f)r two only, 

 tho others enjoying complete immunity. And again, tiiere are gn^at dilYor- 

 onces in tlie degree of the snsce])tibility of dilVereiit individuals. One may 

 }>o violently poisoned by tho emanations from a growing plant, while an- 

 other may re(iuirf( actual contact to produce oven slight manifestations. 

 The poisonous principle is present in all parts of these plants, but is most 

 concentrated in tho milky j;;ico. Tlio other constit>ients are unimportant 

 and inert, being only the ordinary vegetable prineipl'S. 



yVcyw/v^/t'oNs. -None are othcial. Tho fresh loiives of A'. Toxii'ixlcinlroa 

 were admitted into tho Pharmacopceia with the idea that the prescril)er 

 would order a tincture made fx'oin thoni according to the fornnila provided 

 *'">r tinctures of fresh herbs. The other species are susceptible to similar 

 t; ^atmont. There can be no doubt tliat an alcoholic tinc^turo kept tiglitly 

 corked is tho best moans for preserving the drug in at^tivity. 



Medical I'roprrtii'.-i aitd fVcs-. — Here we are altogether in tho dark. 

 Cases ai*e reported of jiersons sut!oring from various cutaneous eruptions 

 having been permanently cured by accidental rhus-poisoning. Cases are 

 now and then reported also of paralytics having been restored liy strokes 

 of lightning, yet paralytics, as a rule, Avould prefer not to undergo such 

 heroic treatment. Granting that it may l)o possible to cure certain skin 

 diseases by this substitutive action, the first thing to decide in a given case 

 would be the susceptibility of the i^ationt to the remedy, and the second, 

 how to Umit its action within reasonal.*. bounds. In endeavoring to settlf, 

 the first by exjieriment, gi'oat risk would bo run of going beyond tho sec- 

 ond altogether ; for as no man Ii'vs yet discovered anything like an infallible 

 remedy for rhus-poisoning, thougii palliatives are numerous, no one is 

 likely to be able to prescribe limits for it when used as a remed)'. Certain 

 it is that rhus will never be very popular as an external application with 

 patients who' like the writer, have experienced its poisonous etfects. Re- 

 garding its use as an internal remedy, still loss need be said. Nearly all 

 the testimony to its value when used in this manner comos from sources 

 discredited in scientific medicine. It is claimed, of course, that it exerts 

 specific eifects in certain cases, even when administered in infinitesimal 

 doses ; but when we consider that personal susceptibility is the first requi- 

 site for any effect whatever, we may well doubt the specific eflfect of even 

 minute doses upon humanity, or disease, at large. Finally, admitting the 

 potency of rhus as a cane j of disease, we have yet to learn its power and 

 mode of use as a remedy. 



