Although William Rivers is now best known for his work in Anthropology and Psychology, he also directed and participated in several important experiments; it was a requirement for lecturers at Cambridge to do this, and to publish research as part of their employment. What made Rivers different is that sometimes he used himself as the test subject.

Like many Victorians, Rivers was keen to understand the effects of various things on the human body and psyche and, for one such experiment, (http://www.jameslindlibrary.org/illustrating/articles/william-halse-rivers-1864-1922) the doctor gave up alcohol and caffience for two years. In order to make the results reliable and without bias, he and his co-worker, Webber, came up with what we now call the ‘Double Blind’ or ‘Placebo’ technique or the use of ‘indistinguishable control mixtures’ as he explained it (Croonian lectures at the Royal College of Physicians, 1908), so that when given a drink he did not know for certain whether it contained the substances or not, and could thus record his reaction without ‘suggestion’ – without his mind assuming what would take place from his knowledge or experience.

A human experiment in nerve division by W. H .R. Rivers MD FRS, Fellow of St John’s College, Cambridge and Henry Head MD FRS, Physician to the London Hospital

More famous was an experiment undertaken with Henry Head between 1903 and 1908. Head was interested in the manner parts of the human body recover from nerve injury and had been studying the patients in the Royal London Hospital but found that what was happening as he needed. Head consulted Rivers and, with the help of Surgeoon James Sherren, they decided that the only solution was for one of them to become the subject, the other the experimenter/ observer. Head was chosen for the former role and in April 1903, Rivers severed his radial nerve in his lower left arm. This meant that the skin at first, on the fore-arm and hand were effectively made numb and the restoration of feeling was chartered periodically over the next five years. Their findings although no longer considered fully explanatory of the regeneration process are still held to be an excellent illustration of what occurs after such a wound.

A much more comprehensive account of the results can be found at http://brain.oxfordjournals.org/content/132/11/2903.full but, in basic terms, it was determined that recovery is not consistent for the entire affected area; parts of the arm became sensitive to stimuli such as pin pricks or heat and cold long before others and, fascinatingly, it was not always possible for Head to locate exactly where on the arm Rivers was applying the objects.

A prick on the back of the wrist might cause pain throughout the whole back of the limb, or all round the base of the hand and, in the earlier stages, the intensity of the pain could be completely out of proportion with what had been done. This type of reaction, they decided to call ‘Protopathic’.

This shows the extent of diminished response (dotted line) in Head’s arm as observed by Rivers on 3rd Oct, 1904. The protopathic area is distinguished by the unbroken line.

Eventually increasing areas of feeling returned and whilst they did so, some developed the ability to be more precise and less likely to cause the extreme widespread discomfort observed before – this became the ‘Epicritic’ stage. Both of these words derive from Ancient Greek ; Proto meaning ‘Primitive’, Pathos; feeling or sensation. Epicritic- to judge or give a judgement of (Greek – Epikritikos ). Head never fully recovered full feeling in the limb; a triangle of skin between his finger and thumb did not return to normal although it did react to the cold. It is likely, however, that this experiment became crucial to the understanding of soldiers’ wounds in the Great War, in which both men served as doctors, not a decade later