( 166 ) 



This seeming contradiction may tie met by the explanation that 

 the exchange of substance between the leucocytes and the solution 

 of NaCl, especially when the hitter is isotonic with the serum, is very 

 small; whilst in the ease of other cells (ciliated cells, muscular fibre 

 cells) the conditions of the exchange of ions are not so restricted, and 

 consequently the chemical structure of these cells is more easily 

 moditied. And it is obvious that a modification of their, chemical 

 structure causes a disturbance in their inherent functions. 



13. From the facts here recorded, it is evident that in studying 

 the action of the phagocytes on bacteria in vitro, the degree of 

 osmotic concentration and of the alkaline reaction of the medium, 

 must be taken into account. This condition has been lost sight of 

 in several of the experiments. They ought therefore to be repeated. 



Groningen, June 1907. 



Chemistry. - - " The decomposition of penta-erythritol tetraformate 

 on heating." By Prof. P. van Romburgh. 



(Communicated in the meeting of June 29, 1907). 



As the heating of the diformate of .->'. divinylglycol had led in such 

 a simple manner to hexatriene 1.3.5, investigations have been set on 

 foot in my laboratory for studying the decomposition of formic 

 esters of polyhydrie alcohols, the results of which will be gradually 

 communicated. 



If for penta-erythritol we accept the formula : 

 HO H,C X /CH 2 OH 



HO H a (X \CH 3 OH 



and if the reaction took place in a similar manner as with s. 



divinylglycol diformate, we might expect on heating the tetraformate') 



the formation of a hydrocarbon of the formula: 



H 3 C X /CH 2 



H a c/ \dH s 



in which occurs twice a 3-ring. 1 ) 



') Gustavson G. R. 123 (1896) 242 obtained from the letrabromide of penta- 

 erythritol, by the action of zinc and alcohol, vinylcyclopropan : 

 H 2 C 



| >CH — CH = CH 2 , 



instead of the abuve cited hydrocarbon. 



