374 Investigations dealing with Phenomena of 11 Clot " Formations. 



which has not yet been isolated,, and which need be neither Lipoid nor 

 protein. Such a gel need not, furthermore, be continuous, but may simply 

 form a matrix, holding together proteins and lipoids and other cell con- 

 stituents. The protoplasm itself may exert its normal functions only when 

 its constituents are held in such a matrix. The amount of substance to 

 which the gel formation may be due need be present only in very small 

 quantities. A solid gel has been obtained with ^-per-cent. solutions of 

 sodium cholate, but the author, in conjunction with Dr. E. Graf von 

 Schonborn (in a preliminary communication to the Biochemical Society 

 last May), has shown that solid gels are formed from sodium deoxycholeate 

 (another bile acid), when the concentration does not exceed 1 in 1000. 



Various other problems arise from the study of these gels. Attention has 

 been called to the fact that relatively large quantities of sodium and 

 magnesium salts are necessary to produce gel formation as compared with 

 those of calcium salts. These facts offer a suggestion as to the antagonism of 

 calcium salts to the toxic action of sodium and magnesium salts, as has 

 been observed by Loeb, in the case of fundulus eggs, and of which many 

 other biological examples exist. The replacement of a calcium salt by 

 sodium or magnesium salts may render a gel unstable. It is proposed to 

 investigate phenomena of this description. In all the above experiments 

 a large excess of calcium salts has been employed in gel formation, in order 

 to accelerate this phenomenon. To obtain results more analogous to the 

 various biological phenomena, it will be necessary to study the action of 

 various reagents on the gel when in thin membranes, and under conditions 

 under which excess of calcium salts can be readily removed.* Preliminary 

 experiments indicate that under such conditions the gel may be reversed. 

 Work is proceeding in this direction, and it is also proposed to employ the 

 gels for the study of various phenomena of permeability. 



* In the above-described experiments the inhibitory actiou of various substances on a 

 membrane (or gel) formation has been studied. It has been assumed in these arguments 

 that the more powerful this particular action of a given substance is, the greater will be 

 its disaggregating action on an already formed membrane (or gel). 



