Professor Mark Cunningham
Head of the Discipline of Physiology, School of Medicine, Trinity College Dublin, the University of Dublin, Ireland

“With the exception of geography, there is no science which has been so susceptible to the rhetorical appeal of cartography as the science of medicine”
Douwe Draaisma (2009)

Last June, The Physiological Society unveiled a blue plaque to celebrate the legacy of Irish physiologist Gerald Francis Yeo (1845 – 1909). Yeo was one of 19 physiologists who gathered at the house of John Burdon in March 1876 to form The Physiological Society for “promoting the advancement of physiology and facilitating the intercourse between physiologists”. Yeo was the Secretary of The Society until 1889 and campaigned for the value of in vivo research in response to Victorian antivivisection campaigns. Professor Mark Cunningham shares the legacy of Yeo’s life and work.

Gerald Francis Yeo was born in 1845 in Howth, County Dublin. The Yeo family arrived in Ireland from southwest England in the late 18th century. Yeo’s father, Henry was a Justice of the Peace and had been the Registrar of the Court of the Exchequer. Yeo was sent north to the Royal School Dungannon, County Tyrone and from there, he entered Trinity College Dublin (TCD) and graduated in Natural Sciences (1867) and an M.B./B.Ch. (1867). Yeo gained valuable research experience during time spent in Paris, Vienna, Leipzig and Berlin. During his time on the continent, Yeo would have interacted with figures such as Carl Ludwig and Friedrich Goltz. Yeo recognises Ludwig as his master in terms of his training as an experimentalist (Royal College of Surgeons) and stated that “I am proud to call him (Goltz) my friend.” (Yeo, 1882)

Back in Dublin, Yeo demonstrated anatomy in the School of Physic (Medicine) at TCD and was appointed as the Lecturer in Physiology at the Carmichael College of Medicine. The Carmichael had been previously known as the School of Medicine of the Richmond Hospital. Alongside his teaching activities, Yeo was active in research. In his monograph on the history of medicine in TCD (Coakley, 2014), Coakley discusses a decline in the Irish School of Medicine, a failure to match developments in biomedicine taking place in countries such as Germany and France being the main cause. Yeo was pushing against this downturn. He published numerous papers in the Proceedings of Pathological Society Dublin and the Irish Hospital Gazette. Yeo’s scientific output at this time included studies on the brain. In 1874, he published a paper in the Proceedings of the Pathological Society (Dublin), describing a particular type of cerebral tumour (Yeo, 1874).

In 1875 Yeo was appointed Professor of Physiology at King’s College London, following in the footsteps of his compatriot and fellow alumnus – Robert Bentley Todd. He was also appointed assistant surgeon at King’s College Hospital. King’s was an exciting environment with Lister, Watson Cheyne and Ferrier active in the faculty. Yeo collaborated with Watson Cheyne who was then a strong advocate of Lister’s antiseptic methods. In 1879, the British Medical Journal reported the proceedings of the Pathological Society of London and described a presentation by Watson Cheyne in which the surgical contributions of Yeo in studies examining the presence of micrococci in wounds treated using Lister’s antiseptic method were acknowledged.

Yeo’s colleague David Ferrier had spent the preceding decade at the West Riding Lunatic Asylum working on experiments that would culminate in his book “The Functions of the Brain.” In 1872, Ferrier had been invited by Crichton-Browne to investigate the findings of Gustav Fritsch and Eduard Hitzig. Using direct current stimulation, they demonstrated cerebral localisation. Fritsch and Hitzig’s work had not been universally accepted and further work was required. Ferrier used both “Faradic” stimulation and surgical ablation in a variety of species to address this. However, the ablation studies were limited as with the absence of aseptic condition, the animals failed to survive much beyond the surgery. Yeo’s surgical skills coupled with his experience with antiseptic techniques provided Ferrier with an ideal collaborator. Additionally, Yeo and Ferrier would use primates rather than dogs. Their scientific opponent was Friedrich Goltz, who refuted the localisation theory and based his objections on studies in dogs.

The denouement took place at the Physiological Section of the International Medical Congress in London in 1881. At the Royal Institute, Goltz discussed a dog with a large area of the cortex removed and how this produced no effect. Goltz argued that this demonstrated the functions of the brain were not localised. Ferrier and Yeo countered that a localised paralysis in their monkey due to the removal of the putative motor area supported localisation (Klein and Langley, 1884).

In his presentation at the physiology section, Ferrier highlighted the contributions of Yeo, stating that:
“….I have had opportunities of observing animals operated upon by my colleague, Professor Gerald Yeo, in an investigation into the application of the principles of antiseptic surgery to lesions of the brain and its coverings.”

Yeo recognised the importance of his contributions, stating:
“Those who have experience of the aseptic method of operation will excuse my presumption in saying that I think absolute localization of the cortical lesion have not been arrived at with at all the same exactness in any set of experiments undertaken without its aid.”

Yeo also played an important role in the scientific relationship – that of the sceptic. This is captured by Yeo’s comments:
“I commenced this series of experiments with distinct misgivings as to the existence of local cortical centres, in Ferrier’s sense, so that I may say I was rather prejudiced against, than in favour of, his views.”

Perhaps Yeo’s initial view of the experiments may have been prejudiced by his friendship with Goltz. Indeed, Yeo took a conciliatory position stating:
“These very remarkable negative results obtained by my friend, Professor Goltz, in the case of dogs, cannot be said to be an adequate argument against the positive results arrived at in our experiments upon monkeys; while, on the other hand, our positive results seem to curtail in an absolute manner the very extensive generalizations Professor Goltz wishes to draw from his experiments.”

The discussion was closed with a decision to form a committee that would examine the brains of both animals. The committee was to assess the extent of the lesion given the conflicting results presented. That afternoon a delegation visited Yeo’s laboratory at King’s to view the animals that had been described in detail during the morning’s section meeting. Goltz’s dog showed an absence of sensory or motor deprivation – the animal responded in a normal manner, running around and reacting to its environment. In contrast, one of the monkeys, which had undergone ablation of the motor area of the left hemisphere, presented with unilateral paralysis of the right arm and leg. Charcot is reported to have exclaimed, “C’est un malade!”. Yeo and Ferrier had recapitulated in the laboratory a condition frequently observed in hospital wards or neurology clinics. The examination of the brains of the animals by the committee supported Yeo and Ferrier’s demonstration of cerebral localisation.

Yeo had contributed to determining that sensory and motor functions were located in the cerebral cortex. His work with Ferrier, like that of Hughlings Jackson and Todd, applied to the neurophysiological origin of epileptic seizures. The use of Yeo and Ferrier’s “functional maps” of the brain, alongside antiseptic surgery, led to the first successful operations to remove a brain tumour.

The events that followed further emphasise Yeo’s crucial role. The emergence of experimental animal studies produced a significant anti-vivisection movement in English society. This movement was led by Francis Power Cobbe, who had established the world’s first anti-vivisection organisation in 1875. Cobbe was influential in the decision made by England to pass the world’s first animal protection law (Cruelty to Animals Act of 1876). The high-profile nature of the 1881 International Medical Congress (and an endorsement of a statement supporting animal experimentation by delegates) meant that the anti-vivisection community were actively targeting experimental physiologists. When news reached Cobbe that Ferrier did not have a licence from the Home Office for the studies he had presented, the scene was set for another showdown. A summons was issued against Ferrier. However, the cross-examination at Bow Street magistrates revealed that Yeo had conducted the experiments per the Act. He had used anaesthetic, had a licence for the operation and a certificate for keeping the animals alive for the duration of the studies. The summons was dismissed.

Yeo’s interactions with Cobbe did not cease here. They participated in a series of vociferous printed debates published in Victorian periodicals (Cobbe, 1882; Yeo,1882). This war of words focused on the moral qualities of the two protagonists rather than the issue of vivisection. The Physiological Society was founded with the aim of the advancement and protection of physiology. With his experience and a track record in public defence of the topic, Yeo made important contributions in advocating scientific research using animals. He was part of a Physiological Society committee that raised the issue of the refusal of certificates from the Home Office and the prevention of experiments taking place due to notification that licences or certificates would not be issued. Ferrier’s trial had elicited donations to assist with any associated legal costs. The British Medical Association subsequently covered the costs and the monies raised were used to establish a Science Defence Association. Yeo was tasked by the Physiological Society with the administration of the subscribers and donations. With the Association for the Advancement of Medicine by Research (AAMR), Yeo was appointed to promote research in physiology and “remove existing practical difficulties associated with the 1876 Act.” Yeo also took on responsibilities of engagement and communication with the medical media and was specifically tasked with looking after communication via The Lancet. However, Yeo’s interactions with the Home Office were not positive. In 1884, he reported to The Society that his work had been obstructed by the Home Office (Sharpey- Schafer, 1927) and in 1884 Yeo was denied a certificate (Lushington, 1884).

Yeo was one of the original founding members of The Society and the first meeting at 49 Queen Anne Street was adjourned to be resumed at his house, 37 Dorset Street. He served as Secretary to The Society from 1876 until 1889. Sharpey-Schafer describes Yeo as “typically Irish….but impetuous, and unyielding in argument, steadfastly declining to be ‘convinced against his will’.” There is evidence to support this statement. Sharpey-Schafer (Sharpey- Schafer, 1927) reported that at a Society dinner, Professor Preyer, who had an interest in hypnotism, found his attempts on Yeo “only served to exhaust the hypnotiser”. Yeo was also a major force, alongside Kronecker and Foster, in establishing the international physiological congresses. Yeo served as the honorary secretary for the first congress, which was held in Berne in 1889 (Franklin, 1938).

The last words should be left to George Romanes, who in reviewing a book written by Yeo, praised the author as ‘something more’ than a man of science and a logician….a man of large and generous heart, of finely strung feelings, and a lover of animals as well as a “lover of men”’ (Romanes, 1883).

References

Coakley D (2014). Medicine in Trinity College Dublin: An illustrated history. (published by Trinity College Dublin, 2014)
Cobbe FP (1882). Fortnightly Review, January, 88-104
Franklin KJ (1938) Annals of Science, 3:3, 241-335
Klein and Langley (1884) Journal of Physiology, Vol. 5, 231
Lushington G (1884) Correspondence of Godfrey
Lushington to Gerald Yeo, March 13, 1884, HO 156/2, 26
Romanes GJ (1883), Nature, 28; 537–8
Royal College of Surgeons England, Plarr’s Lives of Fellows, RCS: E003671
Sharpey-Schafer E (1927). Journal of Physiology 64
(Suppl), 1-76.
Yeo GF (1874). Proceedings of the Pathological Society of Dublin, Vol. 4, 48-50
Yeo GF (1882). Contem. Review, May, 897-898
Yeo GF (1882). Fortnightly Review, May, 352-368
Br Med J 1879;1:776
Br Med J. 1881; 2: 878.
Br Med J 1881;2: 836-842