304 BACTERIA IN CROUPOUS PNEUMONIA. 



identity of the oval or " lanceolate " coccus found by Talamon in pneumonic 

 exudate, and which in his experiments produced typical pneumonia in rab- 

 bits, and the so-called " pneumococcus " of Friedlander, which, according 

 to his account, gave a negative result when injected into rabbits, but caused 

 pneumonia in mice when injected directly into the lungs. Prof. See was 

 not alone in making this inference, which has turned out to be a mistaken 

 one. The identity of the oval cocci, which had now been seen in the pul- 

 monary exudate by numerous observers, with the microorganism which 

 Friedlander had isolated and cultivated from material obtained post mortem 

 from hepatized lungs, was generally admitted ; and all of the observations 

 relating to the presence of oval cocci, having a more or less distinct capsule, 

 in the exudate of fibrinpus pneumonia, were supposed to give support to the 

 alleged discovery of Friedlander. Now we know that the oval coccus most 

 frequently found in such material is not that of Friedlantier, but that it is 

 identical with a coccus first observed by the writer in September, 1880, in 

 the blood of rabbits injected with his own saliva and subsequently (1885) 

 named by him Micrococcus Pasteuri. 



This was, without doubt, the coccus which produced pneumonia in Tala- 

 mon's experiments upon rabbits ; and we must give him the credit of having 

 first experimentally aempnstrated the fact that fibrinous pneumonia may be 

 induced by the introduction of this microorganism into the parenchyma of 

 the lung in these animals. 



Salvioli, whose experiments were also made in 1884, had a uniformly 

 fatal result from the injection of pneumonic sputum into rabbits (four). He 

 also observed the oval coccus in the material injected, and in the blood of 

 the animals which succumbed to his injections, but did not recognize the 

 identity of this coccus with that which my own experiments and those of 

 Pasteur, Vulpian, and others had shown to be present in normal human 

 saliva and to induce a fatal form of septicaemia in rabbits. On the other 

 hand, he also appears to have taken it for granted that the oval micrococcus 

 encountered by him, and which, under certain circumstances, was sur- 

 rounded by a transparent capsule, was the '* pneumococcus " of Friedlander. 

 Klein appears to have made the same mistaken inference. This is shown 

 by the following quotation from his paper published in 1885: 



44 In seeking to ascertain what might be the relation between the so-called 

 pneumococci and croupous pneumonia, I have made extensive examination 

 of the lungs and blood of persons dead of the disease, and also of the sputum 

 of living patients at various stages of their illness. ... In some of the air 

 vesicles, tnough few and far between, there were present undoubtedly the 

 capsulated cocci spoken of by Friedlander and others as pneumococci. . . . 

 As regards the living patients, if we examine tvpical sputum of croupous 

 pneumonia we find, besides numerous red blood discs and white blood cor- 

 puscles, also a few epithelial cells, and in the general gelatinous matrix 

 numbers of microorganisms, chiefly belonging to the species micrococci. . . . 



4 'These are, as far as size and arrangement go, of two principal types: 

 (a) Oval micrococci about 0.001 millimetre in length, occurring isolated, but 

 more commonly as dumbbells and slightly curved chains of four, six, and 

 even eight elements. . . . But in all tnese micrococci the elements are dis- 

 tinctly surrounded by a hyaline zone which, in stained preparations, can be 

 made out as an unstained halo, though in some stained specimens it as- 

 sumes a tint that is fainter than that of the micrococcus itself; this corre- 

 sponds to the capsule of Friedlander, and for this reason he called them 

 capsule micrococci." 



In a footnote to the paper from which I have quoted Klein says: 



44 While this paper is passing through the press I receive from Dr. Stern- 

 berg, of Baltimore, a paper in which he conclusively proves that the mi- 

 crococci of human saliva, which produce in some instances septicaemia on 

 inoculation into rabbits, are identical with the pneumococci of Friedlander, 

 Salvioli, and others." 



My own experiments with pneumonic sputum were made in January, 



