76 LOCAL TLSSUE REACTIVITY 



edematous and reddened area when injected into the skin ol nor- 

 mal rabbits. After decomposition of a lead precipitate of the same 

 filtrate material by means of (N.H.4) 1; S.()4 and dialysis, a marked 

 reaction was obtained by a similar injection; the wheal being 

 about 1.5 cm. in diameter within twenty-four hours. The center 

 \vas alwut 4 mm. in diameter elevated and wide and the surround- 

 ing area was hyperemic. In about four days the central area be- 

 came necrotic and the hyperemia std)sided. The original filtrate 

 (not inoculated, concentrated or dialyzed) failed to give reactions. 

 The concentrated products ga\'e certain color reactions ^vhich are 

 usually associated with the presence of carbohydrates. Small c[uan- 

 tities of nitrogen were also obtained (0.3 to 0.4 per cent) . In the 

 \vork in connection with the phenomenon of local skin reactivity, 

 Ecker and \V^elch (1930) employed seven members of the colon 

 typhoid group of organisms, namely, B. typJiosus, B. paratypJiosus 

 A, B. paratyphosus of Aertrycke type, B. enteritidis, B. paraty- 

 pliosus B of Schottmiiller type and B. colt. The filtrates ^vere 

 concentrated as described above. 



Ecker and Welch compared their filtrates w^ith my "agar wash- 

 ings" filtrates and concluded that my products had the capacity 

 to prepare the skin to the provocative injection of their prepara- 

 tions and vice \ersa. It may be assimied, therefore, that the active 

 principles of tiie phenomenon are preserved in the jjrocess of con- 

 centration and purification of Ecker and Rimington. There is 

 an essential difference, ho^\•ever, between tliese preparations and 

 "agar washings" filtrates, as strongly emphasized by Ecker and 

 Welch and in a recent publication by Apitz (1935^) , i.e., the 

 Ecker-Rimington preparations invariably produce a primary red 

 edematous reaction following the intracutaneous injection, whilst 

 the "agar washings" filtrates produce only an insignificant primary 

 erythema. 



AMMONIUM SULPHATE PRECIPITATION OF B. TYPHOSUS ACTIVE 



PRINCIPLES 



The entire procedine ^vas carried out by me under sterile pre- 

 cautions. The Tl "agar washings" filtrates were fully saturated 

 with ammonium sulphate and kept at room temperature for about 

 twenty-four hours. The mixture was then filtered through hard 

 filtering paper, in a Buchner funnel, by means of negati\e pres- 

 sure. The precipitate was taken off the paper and dissolved in 1 



