“Truth emerges more readily from error than from confusion”

— Francis Bacon

Dogs, they say, are a man’s best friend. Perhaps they would feel less well disposed towards their human masters, however, if they were aware of a bizarre series of experiments performed upon canine-kind from the 1650s onwards. The men behind these weird trials were not lunatics; nor were they criminals, sadists or simpletons.

They were, for the most part, Fellows of the Royal Society, England’s most prestigious new scientific institution, and included such august and celebrated personages as Robert Boyle (1627-91), often described as “the father of chemistry”, and Sir Christopher Wren (1632-1723), the anatomist, architect and designer of St Paul’s Cathedral.

These were brilliant men, giants of their age, towering intellects and figures of great learning – and yet they still once seriously thought it might be a good idea to fill a dog up with soup instead of blood to see what would happen.

The idea now sounds insane, but at the time would have seemed slightly less so. In 1628, William Harvey (1578-1657), court physician to Charles I, had published his De Motu Cordis, in which he detailed one of the most significant medical discoveries of all time, his theory of the circulation of the blood, an idea he had arrived at through a series of experiments performed upon the circulatory systems of various living creatures, including dogs.

Beginning in 1616, Harvey had given a series of lectures in which he had revealed that the heart pumped a fixed amount of blood to circulate through the body’s veins and arteries in a continuous fashion, thus disproving the previously accepted ideas of the ancient Roman physician Galen (c 129-c 216). Galen believed that blood was created inside the liver and became enriched with nutrition by the ingestion of food, a source of energy which was then distributed through the body via the veins.

Meanwhile, a second separate stream of blood, distributed via the heart and the arteries, transported air throughout the body. During this process, old blood was constantly being consumed, and new blood being created in the liver. His experiments on animals, though, led Harvey to realise that if this was really true then the liver would have to be producing prodigious amounts of the red stuff each and every day, far more than it would be possible for the body to absorb.

Instead, Harvey saw that blood in animals – and thus by implication in humans – flowed through an essentially circular system, passing out from the heart through the arteries, and then back to the heart again through the veins.

By the 1650s, Harvey’s findings were common knowledge among well-educated men like Boyle and Wren, but still somewhat uncertain was the precise reason why blood circulated in the first place. We now know that blood cells’ main function is to carry oxygen around the body, but at the time this was not quite so obvious. Harvey himself admitted he didn’t know why blood needed to be pumped so quickly throughout the body; he just knew that it did.

The only way for interested parties like Boyle and Wren to find out for sure what exactly blood could and could not do was to perform some practical experiments upon living beings. As such, in 1656 Wren got hold of a dog, dissolved a quantity of opium in some wine, and then introduced this heroin-like substance into the animal’s bloodstream.

At first the dog seemed reluctant to aid science, and had to be held still while a syringe was inserted into a ligatured vein. Very quickly the drugs worked their magic and the animal became intoxicated, putting up less of a struggle. Wren’s conclusion was that this proved Harvey’s theory admirably, the opium circulating throughout the dog’s whole body via its bloodstream with great rapidity.

Eventually, after being whipped around a nearby garden to snap him out of it, the dog returned to normal, and Wren was able to draw some basic conclusions about how it was that poisons, intoxicants and medicines might be made to work more effectively by injecting them straight into the bloodstream rather than administering them orally. If, today, you have a fear of visiting a doctor for a needle, then this is where the procedure effectively began.

As for the junkie dog, meanwhile – after Wren made his findings public, it became famous and was stolen by someone wanting a celebrity pet!

Wren’s experiments, then, as later written up by his colleague Boyle, gave some suggestion as to the function of the bloodstream. Clearly, its main purpose was to transport things around the body. The question was, what things? Air, most likely (oxygen as such was not then known). Perhaps heat as well, helping regulate body temperature. Maybe it moved around all kinds of things. Possibly it transported nutrition from organ to organ, too, just like Galen had taught?

If so, then perhaps it would be feasible to dispense with solid food altogether, and start injecting nourishing liquid substances like broth and watery pudding intravenously instead? This was the theory of Richard Lower (1631-91), a Cornish physician and correspondent of Robert Boyle. Inspired by Wren’s activities, Lower tried to feed a starving dog by pumping milk and soup direct into its bloodstream, but admitted that the procedure failed – most of Lower’s experimental soup-dogs died, their milky, broth-infused blood curdling within their very veins.

He did not know that, while a substance like alcohol can pass unchanged straight into a living creature’s bloodstream, soup and broth have to be exposed to various complicated chemical processes within the stomach, in which the nutrients they contain are broken down into much smaller molecular components. As such, you could no more fill a dog’s blood full of soup to feed it than you could inject its veins full of Pedigree Chum.

Some of these people have been genuine scientists, and have made real discoveries on to which they have nonetheless then projected their own, often quite aberrant, personal philosophies and belief systems. Others have simply been lone loons, whose pseudoscientific theories have never stood up to the scrutiny of anyone but themselves. Some of these concepts have been accepted by very few; others by millions. History is littered with their wreckage, and this book tells the story of some of the very strangest.

Forgotten Science: Strange Ideas from the Scrapheap of History

Excerpted with permission from Forgotten Science: Strange Ideas from the Scrapheap of History, SD Tucker, Amberley Publishing.