CHEMICAL PHENOMENA IN LIFE 



methods have been discovered. Instead of chloro- 

 form as an antiseptic toluol is generally used, 

 which liquid has scarcely any injurious effect 

 upon the substances of the cell. But, as Palladin, 

 of St. Petersburg, has lately shown that even the 

 grinding down does harm to many vital reactions, 

 it is better to kill the living tissues by freezing 

 and not to grind them. After having been frozen 

 at 20 degrees, and having been placed in a glass 

 with some toluol, the organs are brought back 

 into room temperature. It is said that under such 

 conditions more reaction takes place than when 

 the material is ground down. 



We owe to Edward Buchner, of Wiirzburg, 

 another remarkable method which has the ad- 

 vantage of permitting us to work with liquids 

 without any particles of living cells, as in auto- 

 lytical methods must otherwise always be done. 

 Buchner recommends the material being ground 

 down as finely as possible, and quartz sand or 

 silicious marl being added. The thick paste of 

 cells and silicious powder is then pressed out in an 

 hydraulic press under a pressure of 300 to 500 

 atmospheres. In this way all the cell sap is 

 separated from the solid parts of the cells, and 

 contains but a very small quantity of cell frag- 

 ments. Even these may be removed by filtering 

 through a Chamberland candle filter. The clear 

 cell sap, however, still contains many substances 

 which were hitherto known only in living intact 

 66 



