68 Intracelliilar Conditions [Sept. 



conditions rather than lipon hypotheses relating to them only in 

 gross. 



Intracellular water. When cells are completely desiccated at 

 the temperature of boiling water, they may lose by volatilization 

 more than 50 per cent. of their weight. Some cells lose as much as 

 98 per cent. of their weight under such conditions. The volatile 

 matter consists almost wholly of water, which is quantitatively the 

 leading constituent of living cells. Most of the water in an organ- 

 ism is, as a rule, intracellular in location. 



The temperature of boiling water destroys the life of every 

 known type of cell. This effect is evidently due, in great degree, to 

 influences arising from abnormal vapor tension, excessive hydrol- 

 ysis, destruction of enzymes, and solidification and consequent dis- 

 coordination of the coagulable colloids, which, next to water, com- 

 prise the largest proportion of intracellular material. A moderate 

 degree of desiccation of most animal cells at their normal tempera- 

 tures results in modified function, altered structure, impairment 

 of vitality, or death, or all of these, according to the proportion 

 of water remaining in the cells. Water-bears are among the few 

 animals which may be dried and thus rendered apparently lifeless, 

 but whose form and vital activity are recovered with Immersion 

 in water. Vegetable cells of many types, including bacteria, may 

 be thoroughly desiccated at biological temperatures, until they seem 

 no longer to possess any of the characteristics of living matter. 

 Yet the life activities of such dry cells may be only temporarily 

 arrested, i. e., the cells may be potentially alive. In such cases the 

 cells, after remaining for months or even years in a State of 

 dormant vitality, may be quickly rendered actively alive, if an ade- 

 quate amount of water is supplied. 



Refrigeration, as in the case of high temperature (and for 

 similar reasons), destroys the life of most types of cells, but 

 cells in many of the simpler forms of organisms withstand the 

 destructive influence of solidification of the water in them. The 

 larger the proportion of intracellular water, however, the greater 

 the deleterious effects of freezing appear to be. Destructive effects 

 from the freezing of intracellular water are doubtless due very 

 largely to the abnormality of the new phase relationships thus 

 created in the heterogeneous mass of which each cell is composed. 



