On the basis of the similarity of the reactions 

 of oil emulsions and of protoplasm to mono- 

 and bivalent cations, Clowes has conceived of 

 living protoplasm in contact with water as a 

 system which is, within the protoplasmic mass, 

 a dispersion of proteins, lipoids, etc., in water, 

 and, at its surface, a system of the reverse 

 type, in which water is dispersed in an external 

 continuous fatty or lipoid phase. Clowes does 

 not, however, regard the surface layer of pro- 

 toplasm as a system in which the aqueous phase 

 is wholly discontinuous, but rather as a system 

 in which the continuous lipoid phase is per- 

 meated by water channels, i.e., as an emulsion 

 which is near the reversal point. 



Clowes has assumed that the stabilizer active 

 in the supposed protoplasmic emulsion is 

 either soap or a substance which is like soap in 

 its reaction to mono- and bivalent electrolytes. 

 While soaps are present in protoplasm it does 

 not seem likely that they are the emulsifier 

 which determines the behavior of the supposed 

 living emulsion when other possible emulsifiers 

 such as proteins and lipoids are present in much 

 greater quantities. 



I had the pleasure of discussing phase rever- 

 sal in emulsions with Mr. Hatschek, of London. 

 Mr. Hatschek called my attention to the fact 

 that if the emulsifier in an oil emulsion is some 

 colloid other than soap, for example, gum 

 arabic, the emulsion will not reverse when a 

 bivalent electrolyte is added to it. With the 

 kind permission of Mr. Hatschek I have re- 

 peated and extended his preliminary experi- 

 ments. 



The manner of making the stabilizers and the 

 emulsions, with also the methods employed in 

 determining the type of system, will all be fully 

 described in a subsequent publication. 



Oil emulsions in which sodium oleate or so- 

 dium stearate is the emulsifier are of the oil-in- 

 water type and are reversible with BaCte. 

 —2— 



