392 INFECTION AND RESISTANCE 



animals, added to antigen, would fix alexin. Gay and Southard, 

 Sleeswijk, 24 and others obtained negative results, while Nicolle and 

 Abt, 25 and Doerr and Russ 26 obtained positive results. As far as 

 this particular method is concerned, therefore, no conclusions can 

 be drawn. Sleeswijk, however, has approached the question in an- 

 other way and examined whether or not there is a diminution of 

 alexin in the blood of an animal immediately after anaphylactic 

 shock. He found that this was indeed a regular occurrence, and his 

 results have been confirmed by Friedberger and Hartoch 27 and a 

 number of others. 



Jt was shown by these workers that, both in active and passive 

 anaphylaxis in rabbits and dogs, as well as in guinea pigs, there is a 

 definite and considerable diminution of complement immediately 

 after anaphylactic shock. 



The question now arises : What is the significance of this dimi- 

 nution of alexin? Do the animals die because of a sudden loss of 

 circulating, physiologically necessary alexin, or does the alexin take 

 an active part in producing the conditions which cause death ? 



Either of these possibilities might follow from the mere fact of 

 alexin diminution, but the former the possibility that complement 

 depletion is the cause of death was ruled out by Friedberger and 

 Hartoch. 28 They showed that, by supplying fresh complement to 

 sensitive animals at the time of rein ject ion, shock cannot be pre- 

 vented. They now proceeded to demonstrate the active participation 

 of complement in the production of anaphylaxis. They did this in an 

 ingenious way which depended on utilization of the fact observed by 

 Nolf, 29 Hektoen and Ruediger, 30 and others that hypertonic salt 

 solution (1.5-2 per cent.) will prevent the combination of comple- 

 ment with its sensitized cells. By slowly injecting into sensitized 

 guinea pigs 0.3 cubic centimeter of concentrated NaCl solution 

 just before the injection of antigen they were able to markedly 

 diminish anaphylactic shock saving animals from injections which 

 invariably killed the controls. The force of this experiment we think 

 has been largely eliminated by work of the writer with Dwyer and 

 Lieb 31 in which it was shown that the effect of the salt is upon the 

 rmooth muscle which is rendered less irritable by the salt and there- 

 fore less susceptible to the antigen. 



24 Sleeswijk. Zeitschr. f. Immunitatsforschung, Vol. 2, 1909. 



25 Nicolle and Abt. Ann. de rinst. Past., Vol. 22, 1908. 



26 Doerr and Russ. Zeitschr. f. Jmmunitcitsforschung, Vol. 3, 1909. 



27 Friedberger and Hartoch. Zeitschr. f. Immunitatsforschung. Vol. 3, 

 1909. 



28 Friedberger and Hartoch. Loc. cit. 

 9 Nolf. Ann. de I'Inst. Past., 1900. 



30 Hektoen and Ruediger. Jour. Inf. Dis., Vol. 1, 1904. 



31 Zinsser, Lieb and Dwyer, Proc. Soc. for Exn. Biol. & MecL, Vol. 12, 

 May, 1915, p. 123. 



