3b' AN AMERICAN TEXT-BOOK OF PHYSIOLOGY. 



corpuscles there have come into use in current medical and physiological 

 literature two technical terms which it may be well to attempt to define. 



Globulicidal Action of Serum. — It was shown first by Landois that the 

 serum of one animal may have the property of destroying the red corpuscles 

 in the blood of another animal, thus making the blood laky. This fact, which 

 ha- since been investigated more fully, is now designated under the term of 

 " globulicidal " action of the serum. Jt has been found that different kinds of 

 serum show different degrees of globulicidal activity, and that white as well as 

 red corpuscles may be destroyed. Dog's serum or human serum is strongly 

 globulicidal to rabbit's blood. Tt would seem that this action is not due to 

 mere variations in the amounts of inorganic salts in the different kinds of 

 serum, since the remarkable tact has been discovered that heating serum to 

 55° or 60° C. for a few minutes destroys its globulicidal action, although such 

 treatment causes no coagulation of the proteids nor any visible change in the 

 liquid. Moreover, it is known that foreign scrum injected into the veins of a 

 living animal may exert a marked toxic effect that cannot be explained 

 solely by its globulicidal action — for instance, 7 to 14 c.c. of fresh dog's serum 

 will suffice to kill a rabbit — and lastly, serum is known to exert a similar 

 destructive effect on bacteria, its so-called bactericidal action. These three 

 effects of serum, globulicidal, bactericidal and toxic, seem all to be destroyed 

 I >y heating to 50°-60° C, and it is possible that they arc all traceable to the 

 existence in the blood of some proteid substance, an alexine, which is present 

 in -mall quantity and is different for each species of animal, the material 

 in the blood of one species being more or less globulicidal and toxic, as a rule, 

 to the tissues of another species. 1 



Tsoto i iii- Solutions. — When blood or defibrinated blood is diluted with 

 water, a point is soon reached at which haemoglobin begins to pass out of the 

 corpuscles into the plasma or the serum, and the blood begins to appear laky. 

 It appears that the liquid surrounding the corpuscles must have a certain 

 concentration as regards salts or other soluble substances, such as sugar, in 

 order to prevent the entrance of water into the substance of the corpuscle. 

 Normally the substance of the red corpuscle possesses a certain osmotic 

 pressure which may be supposed to be equal to that of the plasma by which 

 it is surrounded, so that the interchange of water between them is at an 

 equilibrium. If the concentration of the outside Liquid is diminished, this 

 equilibrium is destroyed and water passes into the corpuscle ; if the dilution 

 has been sufficient, enough water passes into the corpuscle to make it swell 

 and eventually to force out the haemoglobin. Liquids containing inorganic salt-, 

 or other soluble substances that possess an osmotic pressure sufficient to pre- 

 vent the imbibition of water by the corpuscles, are -aid to be "isotonic to the 

 corpuscles." Red corpuscles suspended in such liquids do not change in shape 

 nor lose their haemoglobin. When solutions of different substances are com- 

 pared from this standpoint, it is found that the concentration necessary varies 

 with the substance used. Tim-, a solution ofNaClofO.64 per cent, is isotonic 



1 For :i recenl paper .-mil the literature see Friedenthal and Lewandowsky, Arehiv fiir Phys~ 

 - 531. 



