108 MASS. EXPERIMENT STATION BULLETIN 175. 



Table XIII. 



-|-+=very infectious. 

 +=infectious (over 40 per cent.). 



— +=one or two cases of infection, possibly accidental. 

 — =no infection. 



From the preceding table it may be seen that the sap containing the 

 causal agent of the disease varies greath^ in its reaction to so-called anti- 

 septics and other compounds. The writer^ has already pointed out in a 

 previous publication that the influence of certain capillary active sub- 

 stances on enzymes is very variable, aside from the specific toxic quahties 

 of certain of these substances. In comparing the reaction of the sap con- 

 taining the causal agent to certain of these compounds we find that there 

 is a similarity of reaction to that shown by the enzjmies. In the paper 

 above cited it was shown that those compounds which changed the sur- 

 face tension had, as a rule, dependent on their physical properties (hydro- 

 colloidal or lipocolloidal), a certain definite effect on enzyme activities. 



Taking up the discussion of the results in detail we find in toluol a 

 compound which is not soluble in water to any great extent, and hence, 

 behaving like a lipocolloid, having no effect on the action of the causal 

 agent contained in the sap. Toluol, as a rule, has a more or less definite 

 inhibitory action on living organisms. 



Chloroform, when present in the sap not to exceed saturation, behaves 

 also like a lipocolloid, as it is only very slightly soluble in the water, and 



1 Chapman, George H.: The influence of Certain Capillary-Active Substances on Enzyme 

 Activity. Internat. Zeitschrift fiir Physik.-chem. Biologic., I Band, 5 u. 6 Heft (1914). 



