90 
It would accordingly seem necessary to study these two 
processes separately, for instance, by determining the 
quantity of organic food produced in a given period according 
to Weber’s method '), and by experiments for ascertaining the 
intensity of the reduction of carbonic acid at different hours of 
the day. Not till then can we form an idea of the quick 
of transmission by day and of the influence by which i 
affected. 
N ovember 1892. 
1) Arbeiten Wiirzburg 2. - 
