324 DR. WILLIAM ROBERTS. 



blood of a patient suffering from the disease. Experiments 

 made in Russia on individuals who voluntarily submitted 

 themselves to this practice, show that the blood is only in- 

 fective during the paroxysms, but not at the crisis nor 

 during the apyrexial periods. None of the fluids or secre- 

 tions of the body except the blood are infective. All this 

 shows that the virus is intimately associated with the spirilla, 

 and is absent or present in exactly the same circumstances 

 as the latter.^ 



The occasionally observed vanishing and reappearance of 

 the spirilla during the paroxysm, without a possibility of new 

 infection, seems to indicate that when the spirilla disappear 

 they leave behind them something in the nature of seed or 

 spores, from which the new brood springs forth. Ocular 

 evidence of such germs is, however, still wanting. Several 

 observers have noticed minute particles in the blood of re- 

 lapsing fever which might pass for spores, and Heydenreich 

 observed that some of the spirilla had a dotted appearance. 

 But hitherto all efforts to cultivate the spores out of the 

 body have failed, and their power of developing spores is 

 more an inference than a demonstration. 



Splenic Fever. — The first trustworthy observation of the 

 presence of organic forms in an infective disease was made 

 in splenic fever. This formidable disorder attacks sheep, 

 cows, and horses, and is not unfrequently fatal to man. In 

 1855, PoUender discovered minute staff-shaped bacteria in 

 the blood of splenic fever. This discovery was confirmed in 

 a very extensive series of researches by Brauell, and has 

 been corroborated by Davaine and other inquirers in 

 France. 



The bacterium of splenic fever is a short, straight, motion- 

 less rod, about as long as the breadth of a blood-corpuscle, 

 and, so far as is known, it exists in no other form in the 

 living body. It is found, besides the blood, in the spleen, 

 in the lymphatic glands, and in some other tissues. That 

 this organism is the true virus of splenic fever has long been 

 probable ; and the labours of Davaine, Bollinger, Tiegel, 

 Klebs, and, most of all, of Koch, have removed the last 

 doubts on the subject. The work done by Koch is not only 



1 See a paper by Motschuloffsky, in the ' Centralblatt fiir die Medicinis- 

 (Chen Wisseuschaften,' 1876, p. 193. During the paroxysm the blood was 

 infective, whether spirilla were detected in it or not. This agrees with 

 Ileydenreich's theory, that their occasional apparent absence during the 

 paroxysm is due to their being incompletely developed, or immature, and 

 therefore unrecognisable under the microscope. 



