84 LOCAL TLSSLE REACTIVITY 



1 ex. as a ])r()\()(at i\c dose. Tlic results were tabulated by these 

 authors as lollows: 



Intravenous Injection P\ Crude Pi Purified Pj Carbohydrate 



Pi crude o cm. 3x5 cm. 4 x 9 cm. o cm. 



Pi purified 4x4 cm. 2x5 cm. 23 x 15 cm. 5x5 cm. 



P> 4x9 cm. 3x5 cm. 13x16 cm. 5x4 cm. 



Carbohydrate o cm. 5x5 cm. 5x4 cm. o cm. 



Inasmuch as no quantitative estimations were made, the tests 

 may be considered as presiunptive and it seems that the follo^ving 

 conclusions are justihed: 



Pi crude and carbohydrate fractions apparently possessed very 

 small amounts of preparatory factors. They appeared to be able to 

 induce the state of reactivity only provided potent materials as 

 P] purified and P^ were used for intravenous injections. It also 

 may be granted that Pi crude and carbohydrate fractions pos- 

 sessed some reacting potency inasmuch as they ^vere able to elicit 

 reactions in sites prepared by potent fractions. It becomes also 

 obvious from these experiments that Pi ptnified and Po fractions 

 contained most of the active principles of the phenomenon be- 

 cause they gave strong reactions when used for skin-preparatory 

 and provocative injections. The authors attempted to classify the 

 potency of the materials on the basis of the size of the lesion. 

 This, however, is some^vhat dangerous since the size of the lesion 

 does not only depend on the potency of the material but also on 

 its ability to diffuse in the injected site. 



ATTEMPTS AT FRACTIONAL PRECIPITATION OF POTENT BACTERIAL 



FILTRATES 



Recently Apitz (1935^) used the following chemical methods 

 for fractional precipitation of bacterial filtrates potent in the elici- 

 tation of the phenomenon: 



(a) Concentration of active filtrate in vacuo at 37° c. to ap- 

 proximately i/io of the original volume and subsequent pre- 

 cipitation of the concentrate with 95 per cent ethyl alcohol. 



(b) The solution of precipitate from (a) in NaOH. The in- 

 soluble material was designated as the "N" fraction. 



(c) Addition of acetic acid to the solution from (b) imtil 

 precipitation was at a maximum. The precipitate ^vas designated 

 as the "P" fraction. 



(d) Precipitation of the soluti(m from (c) with approximately 

 six volumes of 95 per cent alcohol. 



