Poisonous Experiments

Photo of the descending floor of the cave

Photo of the descending floor of the cave

In 1695 Mead set out on a Grand Tour of Italy. He visited the curious Grotta del Cane near Naples and noted its strange ‘venomous exhalations’. This intrigued Mead, who had a particular interest in poisons. He went on to do extensive research on poisons and venom, and his writings on these subjects led to him becoming regarded as an expert.

I met with Dr Mead to ask him about his work on this dangerous and unconventional subject.

Did your experience at the Grotta del Cane on your tour of Italy prompt you to make more experiments on your return?

I wished to carry my Searches farther, so I used to entertain myself at Leisure Hours with Experiments on Vipers and other Venomous Creatures; examining now and then the Texture of Arsenic, Mercury Sublimate, and the like Malignant Substances.

Rattle-snake with section of rattle and tooth, 1731 © Wellcome Library, London

Rattle-snake with section of rattle and tooth, 1731 © Wellcome Library, London

What were you hoping to discover?

My Design was to try how far I could carry Mechanical Considerations in accounting for those surprising Changes which Poisons make in an Animal Body.

I believe that Mathematical Studies, that is, Demonstration and Truth, are essential for the practice of Physick. Mathematical Learning is the distinguishing mark of a Physician from a Quack. He who lacks this necessary Qualification will be as ridiculous as one without Greek or Latin.

How would you go about extracting the venom?

I have oftentimes by holding a Viper advantageously, and enraging it till it struck out its Teeth, made it to bite upon something solid, so as to void its Poison.

Brown viper with Arum lily, 1731 © Wellcome Library, London

Brown viper with Arum lily, 1731 © Wellcome Library, London

A risky method! Is it true that for one experiment you drank venom?

My Aim was to disprove the popular Notion that Venom is poisonous even if you drink it. I enlisted certain Friends, one of whom dared to taste the Venom undiluted. We all agreed that it tasted very sharp and fiery, as if the tongue had been struck through with something scalding or burning. He who had chosen the undiluted Venom suffered a grievously swollen Tongue, but none of us suffered the Symptoms of Poisoning.

This shows that it is senseless for Physicians to advise against the Removal of Poison from Wounds by sucking. However, in sucking out the Poison, one must take care that there be no Ulcer in the mouth, as this may allow the Venom to enter the Blood.

Infant Hercules Strangling the Serpent, tailpiece from Richard Mead, A Mechanical Account of Poisons, 3rd ed., (London, 1745). © Wellcome Library, London

Infant Hercules Strangling the Serpent, tailpiece from Richard Mead, A Mechanical Account of Poisons, 3rd ed., (London, 1745).
© Wellcome Library, London

In your treatise A Mechanical Account of Poisons (1702), you often refer to classical perceptions of vipers.

The Viper has always been so Notorious for its Venom that the most remote Antiquity made it an Emblem of what is Hurtful and Destructive. Nay, so terrible was the Nature of these creatures, that they were very commonly thought to be sent as Executioners of Divine Vengeance upon Mankind for Enormous Crimes which had escaped the Course of Common Justice.

Does venom lose its potency once out of the venomous creature?

My Experiments have shown this not to be the case. Moreover, the Ancients, who knew much concerning the Nature of Poison, provide many further examples. Galen, mentioning the Story of Cleopatra, relates that she killed herself by pouring the Venom of an Asp into a Wound made in her Arm by her own Teeth.

Do vipers have medicinal qualities of themselves?

Vipers have many profitable qualities. Patients ought to eat frequently of Viper-Jelly, or Broth; or rather, as the ancient manner was, to boil Vipers, and eat them like Fish; if this Food will not go down, tho’ really very Good and Delicious Fare to make use at least of Wine, in which Vipers have for a long time been infused. This will quicken the Circulation of the Blood and scourge the Blood Vessels.

 

Once again, many thanks to Dr Richard Mead for taking the time out of his busy schedule for this interview.

 

The Foundling Museum is exploring Dr Mead ‘in the round’, as a physician, patron, philanthropist and collector, in the exhibition The Generous Georgian: Dr Richard Mead – running until 4 January 2015.

 

The next post will look at Mead’s thoughts on the influence of the sun and moon on our health.


 

This post draws on Mead’s writings to answer a series of questions posed in an imaginary conversation.

Venomous Exhalations

Photo of the descending floor of the cave

Photo of the descending floor of the cave

Dr Mead was fascinated by venom from the very start of his career. While at Leiden University, he took an interest in poisons and their anecdotes, and on his Grand Tour of Italy he was especially intrigued by a cave near Naples where he observed what he referred to as ‘venomous exhalations’. His observations caused the development of his thoughts on why air is so necessary to life.

The cave in question was the Grotta del Cane, found on the shore of Lake Agnano – a lake which fills the crater of the extinct Agnano volcano. In actual fact, it is not a cave, but a volcanic feature called a mofetta, or a fumarole – an aperture caused by the discharge of carbon dioxide. The Grotta is like a small corridor which slopes down into the ground, and it is this sloping floor which gives it its name.

Carbon dioxide is heavier than oxygen, so a shallow lake of noxious gas forms at the bottom of the ‘cave’. People walking inside will not notice any difference because their heads will be above the lake of carbon dioxide. However, smaller animals such as dogs will soon suffocate due to the lack of oxygen.

Etching of Lake Agnano. Three men take a dog into the grotto to demonstrate the asphyxiation of the dog. On the left, two local men suspend an asphyxiated dog in the lake in order to revive it: two tourists attend the experiment © Wellcome Library, London

Etching of Lake Agnano. Three men take a dog into the grotto to demonstrate the asphyxiation of the dog. On the left, two local men suspend an asphyxiated dog in the lake in order to revive it: two tourists attend the experiment © Wellcome Library, London

Visits to the Grotta del Cane became extremely popular with the tourists who flooded into Italy in the eighteenth and nineteenth centuries. So-called guides would demonstrate the deadly effects of the cave by walking dogs inside. When the animals keeled over the guides would take them outside to revive them or throw them into the lake to wake them up. Johann Wolfgang von Goethe, in his Italian Journey (Italienische Reise – published 1816–17), writes about the cave, as does Alexandre Dumas (writing in 1841-1843), who notes this gruesome attraction.

Mead visited the cave in 1695 on his tour of Italy and was extremely interested in the effects of these particular ‘venomous exhalations’. He wrote:

from the Ground arises a thin, subtle, warm Fume, visible enough to a discerning Eye, which does not spring up in little parcels here and there, but is one continued Stream, covering the whole Surface of the bottom of the cave; and has this remarkable difference from common Vapours, that it does not, like Smoak, disperse itself into the Air, but quickly after its rise falls back again, and returns to the Earth.

Mead notes that experiments are often made with dogs in order to demonstrate the deadliness of the fumes, but also mentions other more horrible tests:

Charles the Eighth of France prov’d it with an Ass; and two slaves put into it by order of D. Pietro di Toledo, Viceroy of Naples, with their Heads held down to the Earth, were both kill’d.

A couple of tourists are shown a demonstration of the cave's lethal effects

A couple of tourists are shown a demonstration of the cave’s lethal effects. The guide holds up the dog which has already passed out.

In the text, Mead dismisses the possibility of the fumes being a real poison seeing as any animal that comes out in time will quickly recover. He therefore theorises that “the blood may be supplied with something from the air, whatever it be, necessary to life”. Although Mead would not have known about the existence of oxygen, he understood that the air contains something crucial to life which is then transmitted into the blood through the lungs.

What Mead didn’t know was that there was quite a different mystery to be found at the end of the corridor…

Diagram of the sloping corridor © Rosario Varriale

Diagram of the sloping corridor © Rosario Varriale

In 2001 Rosario Varriale, an expert in caves from the Centre for Speleological Research of Naples, cleared out the interior of the corridor (equipped with an oxygen tank) and discovered a chamber measuring thirty-two square metres at the bottom. The chamber was partially blocked-off, with a stepped “walkway” around the sides, and traces of cocciopesto (pottery fragments mixed with lime or sand used to make plaster or mortar) on the floor. Up in one of the corners of the room was an opening that must once have served as a sort of sky-light. The temperature in the chamber reached as high as 60ºC.

The chamber found at the bottom © Rosario Varriale

The chamber found at the bottom © Rosario Varriale

One theory is that the grotto was dug out to be used as a steam room or thermal bath in the 3rd-2nd century BC. There is a complex of Roman baths from the time of Hadrian, (117-138 AD), nearby. Presumably at this time the carbon dioxide had not yet broken into the chamber, or was somehow kept from building up inside it.

If Mead had known it would have been a perfect mix of antiquities and poisons to match his interests. However, the fumes prevented even him from entering.

 

The Foundling Museum’s current exhibition, The Generous Georgian: Dr Richard Mead, reunites key objects from Mead’s life and collection, including a number of his medical treatises on a broad range of subjects from poisons to the plague.

 

The next post will be an interview with Dr Mead, discussing his experiments with poisons.

The Foundling Laboratory: inoculation and experimentation

Sir William Watson

Sir William Watson

The Foundling Hospital was an ideal testing ground for new medical ideas & methods. The children all followed the same diet and regime, meaning that there were very few variable factors.

This gave doctors a unique opportunity for controlled studies, and Sir William Watson, a physician at the Hospital from 1767 until his death in 1787, took advantage of this to test different methods of smallpox inoculation[1] in one of the first controlled clinical trials.

He was interested in perfecting the procedure of inoculation, and conducted carefully-documented experiments to find the best method. Inoculation involves taking some fluid or pus from someone infected and then pressing it into a scratch in the skin of a healthy person, provoking a mild outbreak of the disease. This outbreak is generally much less serious than if they were to contract it naturally.

Watson tested dozens of foundling children who were being inoculated in the off-site infirmaries to determine the best source of smallpox fluid. There was no consensus at the time and he wanted to find out whether fluid from an early pustule or a more mature lesion would provoke a milder outbreak of the disease in the inoculated patient.

He also tested the efficacy of common treatments of the time to prepare patients for inoculation: which included the use of mercury, jalap, rose syrup and senna (these last three being mild laxatives).

Watson conducted three experiments: one using fluid from an early smallpox lesion; another from a mature lesion; and the last from a late lesion. In each experiment, the children were inoculated at the same time and place, and with the same material. The only difference was the other general medical treatment they might have received. Watson’s systematic research had much in common with modern clinical trials.

his drug jar has the label “SYR: ROSARSOL”, which can be translated from the Latin as “syrup of roses”. This was a preparation mentioned in ancient Greek texts and for many centuries was used mainly as a purgative and laxative. Made in England 1670-1740 © Wellcome Library, London

This drug jar has the label “SYR: ROSARSOL”, the Latin for “syrup of roses”. This preparation is mentioned in ancient Greek texts and for many centuries was used as a purgative and laxative. Made in England 1670-1740 <br> © Wellcome Library, London

To assess the effects of the different procedures he, or rather the infirmary nurses, counted the number of pustules on each child. In the end none of the laxative treatments was shown to be especially useful, although he noted that the use of mercury along with a laxative had less of an effect because the mercury stayed in the body for less time.

The mildness of the outbreak caused by inoculation in fact depends on the mildness of the strain of smallpox which is used. There were about seventeen strains of smallpox around in Watson’s London, split into two groups – variola major and variola minor (the latter being much milder). There is some evidence that the strains present from 1750 to 1850 were milder than those before and after.

Watson’s work laid the groundwork for later advances in inoculation, as well as in the development of controlled trials. The Foundling Hospital was his laboratory.

 

Visit the Foundling Museum’s current exhibition, The Generous Georgian: Dr Richard Mead, which highlights the contribution of an eminent physician, collector and patron to the Foundling Hospital. Find out about Mead’s pioneering role in establishing state-of-the-art medical treatment at the Hospital, including the inoculation of the foundlings against smallpox.

 

My next post will look at a mysterious cave that Dr Mead visited on his tour of Italy, which prompted his deep interest in poisons.


[1] For more information on Watson’s experiments, go to http://www.jameslindlibrary.org/illustrating/articles/william-watsons-use-of-controlled-clinical-experiments-in-1767