70 



The total amount of clieiuiccil energy which was set free in 

 gerniiiiiition was therefore always larger than the quantity of energy 

 given off as heat to the surroundings. A part of the free energy 

 which became available in the process of germination was therefore 

 evidently used for other purposes (osmosis etc.) than for heat-evolu- 

 tion ouly. 



This was however doubtful only on the second day, the evolution 

 of heat on that day was not determined; the loss of energy, cal- 

 culated from the heat of combustion, was however so small in this 

 j)eriod that it is very possible that the evolution of heat at that 

 moment was larger, if afterward it should appear that this is really 

 the case, it would be vei*y intelligible. For in the beginning of 

 germination imbibition will principally take place so that in this 

 case evolution of heat is not at all necessarily connected with chemical 

 transformations. 



The results of this investigation may therefore be summarized 

 as folio u^s. 



The loss of energy calculated from the heat of combustion as 

 well as the evolution of heat increase with the duration of germination. 



Both ai'e small -at the beginning of germination and greatly increase, 

 chietly on the 'S^'^ day. 



The evolution of heat is greatly dependent on the surrounding 

 temperature. 



The optimum of heat-evolution is roughly 35^ 



The total loss of energy during germination at 20° exceeds the 

 loss of energy by evolution of heat at the same temperature. 



Utrecht, 1914. Botanical Laborntorij. 



Chemistry. — '' EqiiUlhria in temarij si/stenis XV". By Prof. F. 



A. H. SCHREINEMAKERS. 



(Communicated in thy meeting of April 124, 1914). 



In our previous considerations on saturationcurves under their own 

 vapouri)ressure and on boilingpointcurves we have considered the 

 general case that each on the three components is volatile and 

 occurs consequently in the vapour. Now we shall assume that the 

 vapour contains only one or two of the components. Although we 

 may easily deduce all appearances occurring in this case from the 

 general case, we shall yet examine some points more in detail. 



