( 649 ) 
So just as for Ad negative (see our preceding paper) we have a 
realisable coexistence-curve liquid-solid, viz. with positive pressures 
above a triple-point S, for Ab positive only when A5 has a suffi- 
ciently high value (here =0,5). For Ad positive this triple-point lies 
at about '/, 7, in accordance with what was found experimentally 
for many substances. 
In how far these results are still subject to modification, when not 
— as was supposed up to now — two simple molecules associate 
to one complex molecule, but more than two, we shall have to 
discuss in a concluding paper. Moreover some remarks will be made 
about some papers by von Wermarn, who lately also concluded to 
the improbability of the TAMMANN melting-point -curve on the ground 
of crystallographic-molecular considerations, and who then already 
stated the probable existence of a critical point solid-liquid, which 
existence, however, has only been raised beyond doubt by our theo- 
retical considerations. 
Physiology. — “On the negative variation of the nervus acusticus 
caused by a sound.” By F. J. J. BuiraNpijk. (Communicated 
by Prof. H. ZwaarDEMAKER). 
(Communicated in the meeting of November 26, 19J0). 
Up till now of the electric phenomena caused by the natural 
irritation of the organs, only those of the retina and of the nervus 
opticus have been investigated. *). 
As I have been told, about 1904 a French investigator observed 
electric currents with a mirror galvanometer, when he connected 
this measuring apparatus with the nervus acusticus of a rabbit and 
a loud sound struck the ear of the experimental animal. 
With the string-galvanometer of EintHoven I succeeded in registrating 
the action-currents of the nervus acusticus suggested by a natural 
irritation. Under ether-narcosis of the experimental animal, electrodes 
of a specific form were placed by means of a trepanation opening 
into the hindmost skull-cavity of a cavia. These electrodes, a thin 
metallic tube, containing an isolated metallic pin were pushed on 
along the side-parietes of the cerebellum, usually after piercing the 
juncture of the floeeulus with the rest of the cerebellum. In this way 
a trial was made to reach the nervus acusticus with the extremity 
1) Vide a. o. EinrnoveN and Jotty. Quart. Journal of Experim. Physiol. Volume I. 
1908 page 373. 
