November 28, 1902.] 



SCIENCE. 



855 



others have already demonstrated that bac- 

 teria may exert their blood-destroying 

 power within the living body. This 

 hsemolytic capacity of microorganisms af- 

 fords an explanation, although certainly 

 not the only one, of the secondary anaemias 

 which are such a marked feature of many 

 infectious diseases, as streptococcic and 

 other septicemias, pneumonia, typhoid 

 fever, scarlatina, and others. The htemo- 

 globinuria which is a recognized although 

 rare complication of various infectious dis- 

 eases may be referable to intoxication with 

 unusually powerful bacterial hsemolysins, 

 or to an exceptional lack of resistance of 

 red corpuscles. 



Haemoglobin, however, is not necessarily 

 present in solution in the blood plasma, 

 for the destruction of the damaged red 

 corpuscles may take place within the large 

 phagocytes of the spleen and the hjemo- 

 lymph glands, as is well known to occur on 

 an extensive scale in typhoid fever and 

 some other infections. A familiar ex- 

 ample of the action of bacterial hsmolysins 

 is the post-mortem reddening of the inner, 

 lining of the heart and blood vessels, an 

 effect which may be due to putrefactive 

 bacteria or may appear very soon after 

 death, especially from septicsmia caused 

 by Streptococcus pyogenes, which, as has 

 been shown, may lake the blood during life. 



The fact that certain common saprophy- 

 tic bacteria may produce energetic htemo- 

 lysins, as pointed out by Kraus and Clair- 

 mont and by Todd, has a possible bearing 

 upon the etiology of certain obscure 

 anasmias not of infectious origin, particu- 

 larly upon the interesting observations and 

 the theory of William Hunter concerning 

 theijf causation by absorption of toxins 

 from the alimentary tract. Todd found 

 cultures of Bacillus megatherium so 

 strongly haemolytie that the intravenous 

 injection of 1 c.c. of the filtrate into 

 guinea-pigs was followed by hsemoglobin- 



uria, 10 c.c. being fatal. Human red cor- 

 puscles are sensitive to this hsemolysin. 



Normal human and other blood serums 

 contain in varying amounts antihsemo- 

 lysins, which protect the red corpuscles 

 from the action of some of the bacterial 

 hifimoljrtic agents. Specific antihsemo- 

 lysins are readily produced by immunizing 

 injections of bacterial hsemolysins, and are 

 generated also in the course of infections. 

 Lang suggests that the augmentation of 

 the osmotic resistance of the erythrocytes 

 which has been noted in some infectious 

 diseases, as well as in icterus and some other 

 morbid conditions, may be a reactive phe- 

 nomenon caused by the presence of hemo- 

 lytic toxins. 



Intimately associated with the hemo- 

 lysins in cultures are the bacterial hemag- 

 glutinins,* substances which have the power 

 to clump red blood corpuscles. Among 

 unicellular organisms both the capacity to 

 produce agglutinins and the aptitude for 

 agglutination seem to be very widely dis- 

 tributed. The bacterial hemagglutinins, 

 in analogy with the bacterial hemolysins, 

 are apparently of simpler constitution than 

 the serum agglutinins, being destroyed at 

 58° C, whereas the latter are not injured 

 by temperatures under 70° C. In order 

 to demonstrate in cultures the hemagglu- 

 tinins it is generally necessary to eliminate 

 in some way the action of the associated 

 hemolysins, which can be done by using 

 small quantities of the culture fluid or by 

 keeping the mixture of fluid and red cor- 

 puscles at zero temperature. 



I know of no observation directly de- 

 monstrative of the action of bacterial 

 hemagglutinins within the living body in 

 infections, but this subject is of such recent 

 knowledge that it has been as yet scarcely 

 investigated. Certainly there are morbid 

 conditions which seem highly indicative of 



* Kraus and Ludwig, Wien. klin. Woch., 1902, 

 p. 120. 



