METHODS OF ELICITATION OF PHENOMENON 195 



stances: 10 per cent solution of ethyl urethane; 1 per cent solu- 

 tion ol calcium gluconate; 3 per cent solution ot atropine; 2 

 per cent solution of pilocarpine hydrochloride, acetylcholine di- 

 luted 1:500; and guinea pig liver extract in an amount of 0.85 

 per cent NaCl solution ecjtial to the moist weight of the liver. 



The ears of rabbits tested were clamped off at the base and the 

 left marginal veins injected with 1 c.c. of a mixture of equal parts 

 of 50 reacting units of meningococctis, Group III (44B) "agar 

 washings" filtrates with each of the above substances in dilutions 

 indicated. The mixtures failed to elicit the state of reactivity. 



Prepardtory hitravenous Injections of Active Principles in 

 Conih/nafioii luith Histdmine. Histamine dihydrochloride in 

 dilution 1:1000 was used. In one group of experiments the sub- 

 stance ^vas injected into the dermis of clamped and non-clamped 

 ears in the vicinity of marginal veins. The preparatory injection 

 of varying amounts of active principles ^vas given immediately 

 after^vards. The clamps ^vere released fne minutes after the in- 

 travenous injections were completed. In another group, histamine 

 mixed ^vith acti\e principles in various proportions ^vas injected 

 intra\enously into clamped and non-clamped ears. The clamps 

 were also removed fi\e minutes after completion of the intrave- 

 nous injection. Large doses of active principles mixed Avith 

 histamine elicited some primary injury in clamped ears. The state 

 of reactivity failed to appear in both groups of experiments. 



Preparatory Intravenous Injections of Active Principles Com- 

 bined ivitJi Adrenalin. The marginal veins of clamped ears Avere 

 injected ^vith 1 c.c. of a mixture consisting of equal parts of 50 

 reacting units of meningococcus. Group III (44B) "agar ^vash- 

 ings" filtrate and adrenalin chloride in dilution 1:1000. The 

 clamps \\ere removed five minutes after the intravenous injec- 

 tions ^vere completed. The mixtures were capable of eliciting 

 se\ere primary hemorrhagic lesions. The primary reactions Avere 

 not augmented by the provocative injection of active principles. 



Preparatory Intravenous Injections of Active Principles in 

 Combination with Pituitrin. Pituitrin in dilution 1:200 was used. 

 In these experiments there were made preparatory intravenous 

 injections of active principles in mixture with pituitrin or simul- 

 taneously Avith intradermal injections of pituitrin in the vicinity 

 of the marginal \ein. In some groups the ears Avere clamped be- 

 fore the preparatory injection and the clamps removed five min- 

 utes after the injection was completed. Intradermal or intrave- 



