Medical life in London, especially for General Practitioners, was tough in the middle of the 19th century. The oversupply of GPs meant that income was low and competition tight. Snow had forged his medical career in this environment after passing his exams and graduating from medical school at the College (of Surgeons) and the (Apothecaries’) Hall.

A turning point in John Snow’s fortunes took place on 16 October 1846. On that day, modern anaesthesia and relief of pain began with a successful demonstration of ether inhalation in Boston, Massachusetts.  William Morton, a dentist, had accumulated wide knowledge about ether and its application while working with his associates and was successful in applying this knowledge for the first time during the removal of a tumour.

A letter describing this demonstration finally reached London in December. The American dentist Dr Francis Booth, who received the letter, together with his English colleague, James Robinson, subsequently used ether for a tooth extraction on Saturday 19 December 1846. Booth had also informed surgeon Robert Liston at University College Hospital about this letter. So 2 days’ later, the first surgery under anaesthesia in England took place.  Medical journals and public newspapers all reported the event. A week after the first surgery under anaesthesia, John Snow was able to attend the second application of anaesthesia in dental surgery, which was again performed by Robinson on 28 December.

Reports of the advent of a drug from America, which could induce insensitivity during surgery, spread fast. The more ‘opportunistic’ members of the medical world quickly devised a variety of inhalers and got straight down to business during the 2 weeks after first hearing the news. However, Snow was appalled by the druggist he encountered after the first demonstration he attended. This particular individual obviously did not have any chemical or pharmacological idea about the agent he was about to administer.

On his return home after this particular demonstration, he decided to dedicate his time to performing a series of experiments with the ether he had obtained from a pharmacist. Based on his previous experiments, he had an established laboratory containing a number of small mammals and birds, which he now used to determine the qualities of ether and also the best method of application.

His first priority was to establish dosage control. He quickly realised that the volatile nature of the agent was the source of its fast acting nature, but also of the difficulties in its application. He established that ether strength was dependent on its temperature, and on 16 January 1847, he presented a preliminary table to the Westminster Medical Society which could be used for calculating ether strength by means of its temperature. A week later, on 23 January, he displayed his first apparatus which was designed to control temperature during the delivery of ether.

If people in the 21st century know about John Snow’s work, it is because of his books such as Inhalation of the Vapour of Ether in Surgical Operations, which was published later in September 1847. But his publications started as a series of presentations and lectures originally given at the Westminster Medical Society in the first weeks of that year, which he later revised and updated for publication.

Up to the publication of this seminal first book, Snow had also designed a portable ether Inhaler, adapted Sibson’s facepiece and had produced a vast number of experiments for lectures and papers in which he had refined his initial theories. From January until September 1847, he had also administered ether 52 times at St. George’s Hospital, and between May and September a further 23 times at University College Hospital. This added practical observations to his experimental conclusions.

Then in November 1847 came an announcement from James Young

Table for calculating the strength of ether vapor.

Simpson, a Professor of Obstetrics from Edinburgh. The new agent, chloroform, had been tested and found to produce a safer and smoother result than ether. Only 10 days after Simpson’s announcement, Snow presented a paper to the Westminster Medical Society comparing the new chloroform to the old ‘Letheon’ (a name Morton had given to ether for patenting).

At that meeting, Snow had with him a sample of the new agent for others to try and admitted that he had done so himself. He had found that it did not make him feel sicker than ether had done. A few days before his presentation, he had also used it with his ether inhaler at St George’s hospital and had noticed that it produced a deeper state of anaesthesia quicker than ether.  Within the 10 days of Simpson’s announcement, chloroform had taken over from ether as Snow’s main research subject.

A turning point in the new agent’s growing reputation came on 28 January 1848 in the form of a 15 year old girl from Newcastle called Hannah Greener. The young girl suffered from ingrowing toenails. During the first of her operations in October 1847, she had been given ether, which had made her giggly and light headed, but had taken away the pain. At the follow up operation on 28 January 1848, she entered surgery acting in an agitated manner and was administered chloroform during the procedure.  After she had quickly blanched and started making moaning noises, the chloroform had been removed and the window opened; she was given brandy and bled in order to revive her, but after 2-3 minutes, she was died.

Discussions and examinations into this unexpected death and a number of further deaths could not prevent the success of chloroform though. As it was cheaper to use and acted more quickly than ether with less agitation from the patient, it therefore established itself firmly – despite its drawbacks.

Title page of John Snow’s first publication on Ether.

Two weeks after Hannah’s death, James Young Simpson came to the conclusion that she must have died of asphyxia, a blockage of the airways, as the dosage itself would have been too small to be fatal. He noted that the brandy administered to restore her must have caused her to choke. Snow also did his experiments and reviews after reading the report in the ‘Lancet’. He disagreed with Simpson’s conclusion and also the coroner’s verdict. A congestion on the lung and heart, which had been shown but not seen in connection with the death, he explained as being caused by the strength of the chloroform administered. As chloroform was administered on a handkerchief, the dose had been much higher than anticipated. This had not been recognised and caused a fatal overdose.

Snow continued to record all administrations of chloroform to different patients over the years. These results were later published in ‘On Narcotism’, the third of his now known great works. This final book was published after his death by his pupil and friend, Richardson. Research into chloroform and other narcotics and, of course, cholera would take up the next 11 years of his life.  However, he also continued the investigation into the deaths from chloroform during surgery.


Duncum, Barbara. 1947. The Development of Inhalation Anaesthesia. London: RSM press.

Snow, John. 1847. On the Inhalation of the Vapour of Ether in surgical Operation. London: John Churchill.

Vinten-Johansen, Peter, et al. 2003. Cholera, Chloroform, and the Science of Medicine: A Life of John Snow. Oxford: Oxford University Press.

To cite this post : Iris Millis, “John Snow, the first English anaesthetist. Part 4-1847, Ether and Chloroform”, Museum Highlights (blog on, February 2nd, 2017. 

[On line]

Img 1033 E1472738103846 225X300

Iris Millis is currently a museum officer at the Old Operating Theatre Museum and Herb Garret. She has previously worked for the Anaesthesia Museum and Bodyworlds. She is member of the History of Anaesthesia Society and the John Snow Society. Follow her on Twitter, @historical_iris.

John Snow, the First English Anaesthetist. Part 4: 1847, Ether and Chloroform
Tagged on: