Medicine in the 19th Century: A Canonical Perspective by Srinivasan Raghavan

I first came across the Sherlock Holmes canon in a small town in India during my mid-teens. At the time I would rush through the pages to reach the end and to discover the solution to the mystery. 

Later, after qualifying as a medical doctor, I revisited the works of Sir Arthur Conan Doyle. It became evident that many of Sherlock Holmes' deductive processes were inspired by medical history-taking and physical examination, which are core aspects of medical training. In fact, Holmes’ character was partially modeled on Dr. Doyle’s teacher at Edinburgh, Dr. Joseph Bell, a physician renowned for his keen observational skills and ability to diagnose patients with remarkable accuracy.

With this in mind, I began focusing on the medical aspects of the stories and tried to reconcile them with contemporary terminology and practices.

While many instances of medical elements are woven throughout the stories, I’ve chosen a few that I think might interest readers.

One term that appears frequently in the canon is “brain fever.” For instance, in “The Naval Treaty," poor Percy Phelps has an important document stolen from him, after which he experiences both mental and physical collapse. He says, “Here I have lain, Mr. Holmes, for over nine weeks, unconscious and raving with brain fever… in my mad fits, I was capable of anything. Slowly, my reason has cleared, but it is only in the last three days that my memory has quite returned.”

It seems Phelps suffered a mental and physical breakdown, and similar references to "brain fever" appear in other stories as well.

In modern mental health, there is a condition known as acute psychosis, defined as a clinical syndrome involving hallucinations, delusions, disorganized thoughts or behaviors, or some combination of these, within an acute time frame (often less than a month). When comparing Phelps’ description of his condition with this definition, we can see some similarities, although the duration of the illness differs.

So, what is brain fever? In modern medical terminology, it would likely be classified as encephalitis, or inflammation of the brain, often caused by bacterial or viral infections.

Can stress cause encephalitis? Yes, in rare cases, stress can trigger an autoimmune response in which the body’s own immune system turns against itself, resulting in conditions like lupus (systemic lupus erythematosus, or SLE).

Did Percy Phelps and others in the canon suffer from encephalitis due to an overactive autoimmune  system triggered by stress, or was it primarily a mental health crisis? We may never know for sure!

Next, let’s turn to Curare, mentioned in A Study in Scarlet, The Sign of the Four, and "The Adventure of the Sussex Vampire." Curare is an alkaloid derived from South American plants, initially used by indigenous people to paralyze animals and birds by coating their arrows and darts with it. Interestingly, those who consumed the poisoned animals were unharmed.

The first well-known form of curare, called tubocurarine, was shipped in bamboo tubes, hence its name. It was later adopted in anesthesia as a muscle relaxant to aid in surgery, used alongside drugs that induce unconsciousness. Today, synthetic muscle relaxants are used, which function similarly to tubocurarine but with fewer side effects.

An important point to note is that curare only works when injected into the bloodstream, not when ingested orally.

In A Study in Scarlet, Jefferson Hope, the avenging angel, claims to use a capsule of curare to kill his nemesis, Enoch Drebber, by forcing him to swallow it. However, this would not be effective, as curare is harmless when swallowed, a fact that Sir Arthur Conan Doyle seemingly overlooked.

Finally, I’ll discuss "The Adventure of the Speckled Band," in which Dr. Grimsby Roylott uses a poisonous snake to kill one stepdaughter and attempts to murder the other. Holmes quickly identifies the snake as a Swamp Adder, describing it as “the deadliest snake in India,” and notes that Dr. Roylott dies within 10 seconds after the snake turns on him.

Unfortunately, Holmes was wrong on both counts. The deadliest snake in India is the King Cobra, whose neurotoxic venom paralyzes muscles, including those responsible for breathing. However, even this venom takes at least 20 minutes or more to kill an adult human being, certainly not in 10 seconds.

The Swamp Adder belongs to the Viper family, and its venom is hemotoxic, meaning that it causes blood clotting and eventually starves the body of oxygen by clogging the Blood Vessels. Hemotoxic venoms generally act more slowly than neurotoxins.

I have more fascinating tidbits of canonical medicine to share, and I hope to do so at some other time. I welcome any questions or comments.

Thank you for the opportunity to present my small monograph to you all.