THE MICRO-ORGANISMS WHICH OCCUR IN SEPTICAEMIA. 67 



cases microscopical examination was deferred till some time after 

 death, when various forms of septic Bacteria had developed, 

 which thej do in these cases with incredible rapidity .1 Those 

 organisms which appear to be really characteristic of the disease 

 are so exceedingly minute that they eluded observation till lately 

 demonstrated by the methods adopted and published by Dr. 

 Koch/ and by the aid of recent improvements in object glasses. 

 I propose here shortly to describe the microscopical features and 

 tbe organisms which I have myself observed, following in the 

 main these methods in an examination of .the subject. 



Septicaemia may be originated artificially in animals, when 

 required for purposes of investigation, by inoculation with a 

 small quantity of decomposing blood ; there is, however, as I 

 have found in the investigations of several years, considerable 

 uncertainty in the infectivity of such blood. The recorded expe- 

 rience of many different observers is very discrepant in this re- 

 spect. I have myself found that it does not generally become 

 infective, i.e. capable of originating specific septicgemia, till 

 towards the tenth day, independently of the temperature at 

 which it is kept. The causes which determine this are ob- 

 scure; though admitting the parasitical origin of the affection, 

 we may suppose that it depends upon the presence and develop- 

 ment of the specific organism derived from the atmospliere. 

 The circumstance that such infectivity occurs more frequently in 

 summer than in winter, and that, too, whether the blood is kept 

 in an incubator or at the temperature of the external air, 

 favours this view. 



It is requisite that small quantities only of such blood should 

 be used to create infection ; one or two tenths of a cubic centimetre 

 (one to three drops) may be used ; with larger quantities com- 

 plications arise and specific infection fails .^ In the experiments 

 to which these observations refer I have used white mice, 

 which are very susceptible to infection with this disease, as they 



* Even the latest writer on the subject, A. Krajewski (' Inaug. Diss.,' 

 Dorpat, 1880, reprinted by Professor Semner in the ' Archiv f. Exper. 

 Path.,' &c., for May, 1881) describes and figures various forms of Bacilli 

 and Micrococci in what is regarded as specific septicaemia, but here infec- 

 tion was originated by the injection of considerable quantities of septic 

 matter, 1 to 2 c.c. The same circumstance of delay, renders it very difficult 

 to draw any certain conclusion from the occurrence of Bacteria in tlie 

 organs of man, where, in ordinary cases, the examination cannot be made 

 for a very considerable time alter death. 



2 'Beit. z. BioJ. d. Pflanzen,' v. Dr. F. Cohn, Bd. ii, H. 1; also, ' Unter- 

 such. iiber d. M\iol. d. Wundinfections Krankheileu,' Leipzig, 1878, 

 recently translated for the New Syd. Soc. by W. W. Cheyne, M.B. 



^ ie. septic infection, as above defined, occurs, and the subject is killed 

 by the toxical action of the products of decomposition in, generally, a very 

 much shorter time than the incubation period of the parasitical atiection. 



