( S2? ) 



As a general result of this iiiNestigation it can be stated that, 

 according to theory, in all three series the number of small deviations 

 is greater than the simple exponential law would require, but to a 

 somewhat less degree than would follow from the law formulated 

 in (6). 



The deviations of barometric pi-essure at Helder are in almost 

 perfect accordance with this frequency law and, therefore, for each 

 month separately with the normal law; the curve of deviations of 

 atmospheric temperature in France still shows many irregularities, 

 but, in general, it accords well with the law of form. (6); the 

 secular variability of atmospheric pressure at Batavia is not regulated 

 by the law of accidental events and its frequency curve shows 

 characteristic peculiarities in different seasons. 



Microbiology. — "Mefhttn r/.v carbon-food ami source of energy 

 for bacteria'. By N. L. S()HNGen. (Communicated by Prof. 

 M. W. Beijerinck). 



Methan, which is incessantly produced from cellulose in the waters 

 and the soil, through the agency of microbes, and which, since 

 vegetable life l)ecame possible on our planet must have been formed 

 in prodigious quantities, yet occurs only in traces in our atmosphere. 



As this gas is very resistant against chemical influences its dis- 

 appearance in this way is highly improliable. But the conversion of 

 methan into carbon dioxid and water produces a considerable quan- 

 tity of heat, and so it seemed worth investigating whether there should 

 exist any organic beings capable of feeding and living on it. 



In the first place green plants were examined as to their power 

 of decomposing methan in the light. To this end some waterplants 

 were chosen, which seemed to offer most chance of success, con- 

 sidering that the formation of methan, as an anaerobic process, takes 

 especially place in stagnant waters. 



In this way positixe results were obtained with several species 

 of plants as CalUtriche stagnaUs, Potamogeton, Eloclea canadensis, 

 Batrachium, Hottonia pcdustris, Spirogi/ra. So, for example, in 

 one of the experiments in the light of a window to the North, 

 with Hottonio pahistris, put in a flask containing 500 cc. of methan 

 and 500 cc. of oxygen, and inxersely placed in a vessel filled with 

 water, all the methan disappeared from 7—21 May, so within 

 a fortnight. 



