32^ DR. WILLIAM ROBERTS. 



detected in any of the fluids or secretions of the body except 

 the blood, nor in any other disease than relapsing fever. In 

 form and botanical characters they are almost identical with 

 the Spirochaeteplicatilis of Ehrenberg {Spirillum of Dujardin), 

 a species of bacteria found in dirty water and occasionally in 

 the mucus of the mouth. Cohn designated the variety found 

 in the blood S. Ohermeieri, in honour of its discoverer. 



In the beginning of the current year. Dr. Heydenreich^ of 

 St. Petersburg, published an elaborate monograph on this 

 subject, which, I think, goes far to reconcile the conflicting 

 statements and opinions put forth by previous writers in 

 regard to the connection of the spirilla with relapsing fever. 

 It is based on forty-six cases ; these cases were studied with 

 the most minute care ; ihe blood was examined, and the 

 temperature observed from two to six times each day. Al- 

 together, over a thousand examinations of the blood were 

 made. 



Relapsing fever still prevails extensively in certain districts 

 of Germany and Russia, but it is almost a forgotten disease in 

 this country ; and probably the majority of those in this room 

 have never seen a case. It will, therefore, not be amiss if I re- 

 mind my hearers, and myself, of its principal features. It is a 

 contagious epidemic fever characterised by a sharp paroxysm 

 of pyrexia, which lasts about a week, and ends with a severe 

 critical sweating. This is succeeded by an intermission, also 

 of about a week, during which the patient is apyrexial ; then 

 follows a second paroxysm, or relapse, which lasts four or 

 five days, and ends, as before, in a critical sweating. Re- 

 covery usually follows the second paroxysm, but not unfre- 

 quently a third paroxysm occurs, and sometimes a fourth. 



The paroxysms are occasionally broken by remission or 

 pseudo-crises ; and the apyrexial periods are sometimes inter- 

 rupted by slight temporary rises of temperature. 



Bearing these characteristics in mind, we shall be able to 

 understand the significance of Heydenreich's observations. 

 He found that every rise of temperature, whether that of the 

 true paroxysm, or thatfo]lowingapseudo-crisis,orthose occur- 

 ring during the intermissions, was invariably preceded by the 

 appearance of spirilla in the blood. They disappeared entirely 

 shortly before the crisis, and remained absent during defer- 

 vescence and the subsequent apyrexial periods. During the 

 whole of the main paroxysms spirilla were usually to be found 

 in the blood, but their number varied in the most puzzling 

 manner from day to day. One day they were abundant, the 



1 L. Heydenreicl), ' Ueber den Parisiten des lliickfallstyphus,' Berlin, 

 1877. He gives a good resume of the literature of the subject. 



