( 585 ) 
this experiment, not with garden soil for infection material, but by 
using the stomacal contents of such a case of stomacal sarcine. The 
“not cultivability’ of pr Bary may mean the same as anaerobiosis, 
for it is well known how difficult if is, even at the present time, 
to cultivate anaerobies if the particulars of their life conditions are 
not exactly known. 
For the rest I do not doubt of the precision of FALKENHEM's *) and 
Mievra’s *) observations, wno have seen aerobic colonies of micrococci 
originate from stomacal sarcine. It is true that I for my part have 
not succeeded in confirming this observation with regard to the 
fermentation sarcine, but for other species of Sarcima 1 have, with 
certainty, stated the transition into micrococci, and with various 
anaerobies, although not belonging to the genus Surcina, I have seen 
now and then colonies originate of facultative anaerobics, which in all 
other respects, corresponded to the obligative anaerobics used for the 
cultures. Therefore this modification also seems possible for some 
individuals of the fermentation sarcine. Accumulation or transfer 
experiments with stomacal contents will however only then give 
positive results, if these are used when still in fermentation; with 
long kept material nothing can be expected. 
Already the older observers*) as SCHLOSSBERGER (1847), SIMON 
(1849) and Cramer (1858) have tried, although in vain, by a kind of 
accumulation experiments, to cultivate the stomacal sarcine, wherefore 
they prepared, as nutrient liquid, artificial gastric juice with different 
additions. Remarkable, and illustrating the biological views of 
those days, is the fact, that for the infection they did not use 
the stomacal contents themselves, but beer yeast, supposing, that the 
sarcine might originate from the yeast cells, which somewhat resemble 
it, and are always found in the stomach together with the sarcine 
itself. 
Physics. — “The motion of electrons in metallic bodies.” U. By 
Prof. H. A. Lorentz. 
(Communicated in the meeting of January 28, 1905). 
§ 11. By a mode of reasoning similar to that used in the last §, 
we may deduce a formula for the intensity ¢ of the current in a 
closed thermo-electric circuit. For this purpose we have only to 
suppose the ends P and Q, which consist, as has been said, of the 
1) Archiv f. experiment. Pathologie und Pharmacologie. Bd. 10, pg. 339, 1885. 
2) System der Bacterién. Bd. 2, pg. 259, 1900. 
3) Cited from Surtnear (I. c.). 
40 
Proceedings Royal Acad. Amsterdam. Vol. VIL. 
