^]\6 LOCAL TISSUE REACTIVLIY 



some ral)l)its within one to li\e hours lollowiiio the intiaxenous 

 injection. In survivors, the plienonienon was very marked. Hovv- 

 ever, it is noteworthy that it rabbits were made very sick by the 

 intravenous injection, less marked reactions ^vere obtained. 



Riley and Wilson (1932) compared the general toxicity and 

 phenomenon-producing {potency of various meningococcus prep- 

 arations. The general toxicity was studied in mice. They con- 

 sidered the preparations as toxic if they killed a mouse injected 

 intraj)eritoneally in less than forty-eight hours. They found that 

 preparations containing the products of cell disintegration vvere 

 more toxic than filtrates of culture washings and also that the most 

 toxic of all Avas a defatted meningococcus antigen made by ex- 

 tracting the cells in alcohol and ether and grinding them in a 

 mortar. All these preparations produced the phenomenon and 

 killed mice in a somewhat irregular manner. The experiments 

 seem to indicate that the same toxic substance was present in all 

 the preparations and no actual separation was obtained. The only 

 possible conclusion is that there is a parallelism between the gen- 

 eral toxicity of the materials and their phenomenon-producing 

 potencies. It is somewhat surprising that the "agar Avashings" til- 

 trates were of low general toxicity and of lovv phenomenon-pro- 

 ducing potency in the hands of these authors. As pointed out on 

 numerous occasions, there are a nmnber of factors to be taken 

 into consideration which may interfere ^vith the potency of the 

 "agar washings" filtrates (salt concentration of medium, peptone, 

 incubation temperatme, selection of strain, etc.) . It ^vould be 

 of interest to repeat the experiments of Riley and Wilson by 

 comparing potent "agar washings" filtrates with the defatted 

 meningococcus antigens and cellular suspensions. 



Sickles (1931, 1934) made parallel studies on the phenomenon- 

 producing and lethal effects of purified preparatic:)ns of meningo- 

 coccus. Fractionations ^vith alcohol were made accordino to the 

 methods of Raistrick and Topley. The toxicity of alcohol pre- 

 cipitates (50^- 68, and 9^5 per cent) including the v\ater soluble 

 residue were tested by intradermal injection of 2 and 4 mgms. 

 in mice and by means of the phenomenon. According to prelimi- 

 nary reports of Sickles, evidences of toxicity of some of the frac- 

 tions were demonstrated by both methods. Positive results were 

 not obtained by both methods in every case. In some instances, 

 mice were killed ^vhen no hemorrhagic skin reaction vvas induced 

 and with one carbohydrate fraction, the reverse occurred. 



