It has an extraordinary power over the pain of acute gout; it lessens the severity and frequency of the attacks when given continuously between them, and it markedly controls such symptoms of gout as eczema, bronchitis and neuritis, whilst it is entirely inoperative against these conditions when they are not of gouty origin.
In the effects of simpler poisons the recognition of unity in diversity, as in the affiliation of a peripheral neuritis to arsenic, illustrated more definitely this serial or etiological method of classifying diseases.
Diphtheria, long no doubt a plague among mankind, was not carefully described until by Pierre Bretonneau in 1826; and since his time our conception of this disease has been extended by the study of later, secondary and incidental phases of it, such as neuritis, which had always formed part of the diphtheritic series, though the connexion had not been detected.
Influenza, again, was well known to us in 1836-1840, yet clinical observers had not traced out those sequels which, in the form of neuritis and mental disorder, have impressed upon our minds the persistent virulence of this infection, and the manifold forms of its activity.
Beri-beri is a dietetic deficiency disease which manifests itself by cardiac weakness with shortness of breath, swelling of the legs and peripheral neuritis with numbness of the limbs and weakness.
In 1900 an outbreak of "peripheral neuritis" with various skin affections occurred in Lancashire, which was traced to beer made from glucose and invert sugar, in the preparation of which sulphuric acid contaminated with arsenic was said to have been used.
But sooner or later peripheral neuritis develops, usually beginning with sensory disturbances, tingling, numbness, formication and occasionally cutaneous anaesthesia.