154 LOCAL TISSUE REACTIVITY 



readings ol lincc .sur\i\iii^ ial)l)i(s ol e;u h pr'-paratioii tested were entirely 

 negalivc. 



Unpublished observations on the skin-preparatory effect of various 

 non-bacterial substances: 

 All llu' tests were performed iniilornily. Iwenty-five c.c. of the material 

 were used for the intradermal injection, 50 reacting units of B. typhosus were 

 injected intravenously two. six, and twenty-four hours after the preparatory 

 injection. The experiments were repeated until there were obtained at least 

 3 rabbits which survived the intravenous injection for a period not less than 

 twenty-four hours. If no reference is made as to the residts oi)tained with the 

 substances described, it is to be understood that the skin-preparatory effect 

 of the substances enumerated below was uniformly negative and that primary 

 local reactions (i.e., swellings, erythemas, hemorrhages, necrosis and pus for- 

 mation) were not enhanced following the provocative injection of the potent 

 bacterial filtrate. If any of the substances desciibed were used either in com- 

 bination with a bacterial filtrate, or preceding or following an intradermal 

 injection of bacterial filtrate, description will be given thereof. The sub- 

 stances were as follows: 



Spleen, liver, adrenals, kidney and brain extracts: 



The organs were obtained from guinea pigs and rabbits, ground in a 

 mortar and suspended in an amount of saline equal to the moist weight of 

 the tissue. The supernatant fluid of the extract centrifuged at low speed for 

 a fcAv minutes was employed. Experiments were also done with guinea pig 

 li\er and spleen extracts, frozen and thawed four times during a period of 

 several days. 



Sera treated with agar: 



Agar was used in the final concentration of 0.5 per cent dissolved in 0.85 

 per cent NaCl solution. Horse serum was mixed with agar. The final con- 

 centration of agar was 0.2 per cent. These mixtures were employed immedi- 

 ately after preparation and also were previously incubated at 37° c. for one 

 hour, rapidly chilled and centrifuged. Agar in the above final concentration 

 was also added to rat oxalated plasma, rat serum and ox serum. The methods 

 employed in the preparation of these mixtures were those described by J. 

 Bordet (1913) and Novy. DcKruif and Novy (1917) for preparations of 

 anaphvlatoxins. 



Calcium gluconate: 



Ten per cent solution of calciiuu gluconate was used. 



In addition to the tests on the skin-preparatory potency, the effect of 

 calcium gluconate upon the skin-preparatory factors was tested. The sub- 

 stance was mixed with B. typhosus "agar washings" filtrates before the in- 

 jection; and in other experiments injected into sites prepared with bacterial 

 filtrates immediately before the provocative injection. The reactions of the 

 phenomenon were not modified. 



