TEXT-BOOK OF BACTERIOLOGY. 287 



the bacteria subcutaneously and also by direct injection into the 

 abdominal cavity. But Weisser avoided injection into the lungs, 

 and justly pointed out that we will thereby obtain anything else, 

 rather than (as Emmerich thinks) "an imitation of the natural 

 mode of infection by inhalation." 



Of the animals thus treated, about one-half perished after infec- 

 tion. Death ensued, as a rule, within the first twenty-four hours 

 without having been preceded by especially striking symptoms 

 peculiar to cholera, " above all, without vomiting and without liquid 

 or even pasty evacuations from the bowels and without spasmodic 

 attacks/' 



The post-mortem examination shows the intestinal canal mod- 

 erately filled with liquid. The mucous membrane is of a grayish- 

 red color; the walls have the usual appearance and normal thick- 

 ness. Peyer's patches are slightly swollen and reddened only in 

 rare cases. This picture is, therefore, not to be compared with that 

 presented with the genuine cholera of Guinea-pigs, as we have 

 here an intestine filled with fluctuating liquid, the membrane being 

 of a lively rose-red color and Peyer's patches swollen and peculiarly 

 altered. 



The Neapolitan bacteria can be easily proved to exist in the in- 

 testinal contents, in all internal organs and in the blood, and are at 

 once perceived in cover- glass preparations and in sections. The 

 latter are stained with fuchsin in the usual manner; the bacilli are 

 decolored by Gram's method. They are found in the vessels ex- 

 clusively and do not appear in large numbers. They form swarms in 

 the smallest vessels and capillaries, in whose midst they accumu- 

 late so densely that they can no longer be recognized singly, while 

 their arrangement becomes more transparent toward the margin. 



The results of transmission are, therefore, certainly not apt to 

 strengthen the belief in the significance of the Neapolitan bacilli in 

 the etiology of cholera asiatica. The other conditions for recog- 

 nizing a kind of bacterium as specific, according to our view, are 

 still less fulfilled. 



Emmerich himself has admitted that his bacilli cannot be 

 proved to exist in all cases of cholera. 



Emmerich had obtained the Neapolitan bacillus from the organs 

 of cholera corpses by putting small pieces of tissue into gelatin free 

 from germs and examining the gelatin about one to two weeks 

 later. He thereby renounced every certainty of his observations 

 and sinned against the first requisite of a correct bacteriological 

 investigation, that of conducting the process, above all things, by 

 the approved plate procedure, and of effecting as soon as possible 



