Not all deadly poisons available to the ancient poisoner came from plant sources. Cantharidin is a substance emitted from several species of the blister beetle, sometimes known as Spanish Fly. In The Well of Urd, the courtesan Cyra buys a vial of it and quietly pockets a vial of aconite, with the intention of placing both in a cosmetic cream for her intended target. From her conversation with the apothecary, it is clear this is not the first time she has made this purchase:
Only once had she purchased the scarlet bottle. She had sworn she never would again. Yet now she lifted her finger and pointed to it. His teeth flashed in a sardonic laugh. “Oho! Little Cyra seeks to lift the members of her male companions. If I recall that did not go so well last time you tried it. Perhaps you may wish to reconsider?” Nevertheless he pulled the little tear drop bottle from its resting place in the wooden rack next to its companions. “Blister beetle.” He chuckled and swirled the liquid around and watched the light catch the deep red of the bottle. “So many men so eager to try it. In low enough doses it make them stand as stiff and tall as a wooden post. They pleasure the ladies all night.” He leered at her. “And when they finally can come down, hours later, they spend days pissing blood. Is that not what happened to the vestarches you entertained last year?” He laughed when she grimaced. “It is over and done. He was a fool and should have known better. He was lucky. Some die from the elixir of the blister beetle. Yet you will purchase it again?”
Yet Cyra does purchase it again. With such a risk at ingesting it, what made anyone desparate enough to try it? Cathardin, is a burn agent, potent enough to cause the skin to raise in painful blisters and dangerous enough to actually burn the insides of those foolish enough to ingest it. The Marquis de Sade was reported to have been put on trial for the death of two prostitutes to whom he gave cathardin-laced pastilles. It was his intention that the prostitutes would fall into his amorous embrace due to the supposed aphrodisiac nature of the poisonous pastilles. Instead they both died agonizing deaths, hardly a sexy way to end the evening.
Due to the fact that is odorless and colorless it no doubt made a wonderful candidate for the repertoire of the especially fiendish poisoner. Because of the vesicating nature of the chemical, it was ideal to use dermally as well. This was the very plan Cyra had in mind as the cathardin would open up the skin, making way for the even deadlier aconite. Typically, it takes twenty-four to forty-eight hours for the blisters to emerge on the skin, eventually rupturing and leaving something akin to second degree burns.
Taken internally, it literally burns the interior of the gastrointestinal and genitourinary tract. By those intending to use its doubtful aphrodisiac properties, the intention is to cause priapism of the penis, from genitourinary irritation engorging it with blood and serving as a sort of primitive Viagra. However, the intended erection turns out to be unpleasant and even painful and when finally flaccid, results in painful and bloody urination for some time after, assuming the unwary experimenter lives. There are many accounts of death from ingestion of catharidin. It was as feared as many of its more famous counterparts in poison. So much so that Byzantine law heavily regulated them. The Digest of Roman Law, compiled by the Eastern Roman Emperor Justinian in the 6th century CE, clearly states in regards to murders and poisoners:
It is laid down by another decree of the senate that dealers in cosmetics are liable to the penalties of this law (the Lex Cornelia on murderers and poisoners) if they recklessly hand over to anyone hemlock (cicuta), salamander, aconite, pine-worms (pitupcampae) [a caterpillar with extremely irritating hairs] or buprestis [a species of blister beetle], mandragora [mandrake] or, except for the purposes of purification, catharsis beetle.
Brackets mine for the purposes of clarification.
Whether such laws applied to every part of the empire, even in as far-flung areas as Roman occupied Antioch, my research failed to unearth. It is reasonable to assume that at the very least, apothecaries selling such substances would be wary that charges might be brought against them, should their merchandise happen to be the cause of death of anyone with litigious relatives. The one purchasing such items also had no guarantee that said items were everything an apothecary claimed they were. Then, as now, caveat emptor. The very real danger in cathardin as it is today, is that there is no antidote. Unlike poisons such as aconite which operate on the body with toxic alkaloids and therefore have an antidote, cathardin is corrosive and is akin to ingesting or touching battery acid. It destroys the tissues it comes in contact with. It is, as it was in Byzantine time, heavily regulated and for good reason. Few doctors in the U.S. use cathardin for wart and tattoo removal any longer, preferring salicylic acid and liquid nitrogen instead. Its use has almost been made a joke of in popular culture. But as we have seen, the blister beetle and its deadly elixir was certainly no joke at all.
Resources:
“BOOK FORTY-EIGHT.” In The Digest of Justinian, Volume 4, edited by WATSON ALAN, 309-77. University of Pennsylvania Press, 1998. http://www.jstor.org/stable/j.ctt3fh9jv.12.
Medical Toxicology of Natural Substances: Foods, Fungi, Medicinal Herbs, Plants and Venomous Animals by Donald G. Barceloux 2012
The American Dispensatory, Containing the Natural, Chemical and and Pharmaceutical and Medical History of Different Substances Employed in Medicine by John Redman Coxe 1831
Cantharidin. (2018, January 16). In Wikipedia, The Free Encyclopedia. Retrieved 13:53, January 20, 2018, from https://en.wikipedia.org/w/index.php?title=Cantharidin&oldid=820699738