STUDIES OF DIFFUSION THROUGH RUBBER 



MEMBRANES 



I. Preliminary observations on the diffusibility of lipins and 



lipin-soluble substances 



WILLIAM J. GIES 



(Biochemical Laboratory of Columbia University, at the College of Physicians 



and Surgeons, New York) 



CONTENTS 



I. Introduction c :- 



IL On the diffusibility of biological substances through rubber cg 



III. A demonstration of osmotic pressure exerted by fat 50 



IV. A demonstration of the diffusion of pigments from fat through rubber 



into fat 60 



V. Comparative dialysis experiments, with demonstrations 61 



VI. Experiments on the diffusibility of alkaloids through rubber 62 



I. INTRODUCTION 



When I proposed to my biochemical associates in Cancer re- 

 search, in 1909, that we undertake a study of intracellular chem- 

 istry/ I realized that new analytic methods and unconventional 

 experimental procedures were prerequisites for material progress in 

 this as in any other chemical relation. The greatest obstacle in the 

 path of progress in intracellular chemistry is the evident lability of 

 the essential intracellular constituents. Our best chemical methods 

 increase this predicament because each is essentially anti-biological 

 in character. Biochemical discoördinations are enforced whenever 

 any of our present chemical processes is efifectively applied to proto- 

 plasmic material. 



In reflecting on the properties and possible coördinations of 

 intracellular lipins, it seemed probable that such lipins might be 

 separated from protoplasmic material with the least chemical vio- 



* Gies : Studies in cancer and allied subjects, conducted under the auspices of 

 the George Crocker Special Research Fund; Volume III, Department of Bio- 

 logical Chemistry, Introduction (in press). 



55 



