Q1Q ACUTE INFECTIOUS DISEASES. 



be rejected, for, in that case, we should be inferring a generatio aequir 

 voca, which has been disproved ; but it has not by any means been 

 proved that, besides purely miasmatic affections, whose germs develop 

 outside of the organism and are not reproduced in the bodies of pa- 

 tients suffering from them, there are no miasmatic-contagious dis- 

 eases, whose germs develop outside of the body, but are also repro- 

 duced in the bodies or dejections of patients suffering from them. I 

 know of no absolute objections to this theory, and a series of facts 

 agrees better with it than with the unproved assertion that there is no 

 miasmatic-contagious disease. We not unfrequently see the disease 

 in question appear under circumstances which render origin from con- 

 tagion very doubtful ; for instance, in ships at sea (ship-fever), in care- 

 fully-guarded prisons (jail-fever). On the other hand, under certain 

 circumstances, which appear favorable to low organisms and to their 

 reception into the body, as in years of famine, where bad, spoiled food 

 is eaten (famine typhus) and in over-filled lazarettos, where the air is 

 loaded with exhalations from the patients (lazaret-fever), exanthematic 

 typhus occurs so frequently, that, where these circumstances prevail, 

 its appearance may almost be predicted. Of course, this does not prove 

 that the body of a patient diseased by the introduction of these germs 

 may not be a more favorable soil for its development and reproduction 

 than decomposing flesh, or the air of a lazaretto overloaded with ex- 

 cretions, and that the disease may not only continue to exist, but to 

 extend and even spread greatly, long after the disappearance of the 

 circumstances which favored the development of the germs of the dis- 

 ease outside of the body. If the above-mentioned assertion, that the 

 cholera-germ is developed on dried rice, should be confirmed, it would 

 be still more probable that the germ of exanthematic typhus developed 

 outside of the human body in decomposing animal matter, and when 

 circumstances were peculiarly favorable, increased so as to become 

 dangerous to man. The susceptibility to the miasm or contagion of 

 exanthematic typhus is very general. Males and females, strong, 

 healthy persons and weak, sickly ones, are about equally liable to the 

 disease. Only early childhood and extreme age are usually exempt. 

 Excessive exertion and other debilitating influences appear to in- 

 crease the predisposition. One attack seems to destroy the suscepti- 

 bility to the affection. 



Griesinger and Hirsch speak of the geographical extension of ex- 

 anthematic typhus in Europe thus : from the beginning of the sixteenth 

 to the end of the eighteenth century, this disease extended over all 

 Europe as the common form of typhus ; during the war, at the. com- 

 mencement of this century, it attained its height. After that time 

 it was so rare on the continent, that there was a current belief thai 



