1881.] 



Dr. E. J. Mills. On Melting Point. 



203 



time and increases it at another, and it is also shown that the 

 times of this diminution and increase correspond respectively to the 

 periods when the vagns causes a diminution and increase of the size 

 of the contractions. 



The action of the vagus upon the muscular tissue of the ventricle is 

 further shown by its power of removing the inequalities in the size of 

 the ventricular contractions, when as often happens, the ventricle is 

 beating with alternately strong and weak contractions. 



Stimulation of the nerve causes this inequality to disappear when it 

 increases the force of the contractions, and to reappear again when it 

 diminishes that force. 



The effect of stimulation of the vagus upon the tonicity of the 

 ventricle was studied by the method described elsewhere,* and the 

 author shows that the relaxation between the beats of the ventricle is 

 increased during the stimulation of the nerve, even although the rate 

 of rhythm is not made slower. 



The conclusion therefore is drawn, that stimulation of the vagus acts 

 upon the muscular tissue of the ventricle in such a way as to diminish 

 its excitability and lower its tonicity, when it reduces the force of 

 the ventricular contractions, while it increases its excitability and 

 possibly also increases its tonicity when it augments the contraction 

 force. 



Finally, it is shown that atropin removes the whole action of the 

 vagus stimulation, and the effects of the local application of curare, 

 muscarin, and atropin are described and discussed. 



In conclusion, the author sums up the results of these experiments, 

 and suggests that a series of formative processes are going on in both 

 the muscular tissue and the motor ganglia of the heart, similar to 

 those which occur in gland-cells, and that the vagus produces all its 

 effects by increasing the activity of these processes and not because it 

 contains a multiplicity of fibres, each of which possesses a different 

 function. 



III. "On Melting Point." By Edmund J. Mills, D.Sc, F.R.S., 



Young Professor of Technical Chemistry in Anderson's 

 College, Glasgow. Received December 6, 1881. 



(Abstract.) 



The investigation, of which the memoir contains an account, was 

 undertaken in order to determine, with considerable accuracy, the 



* "Journal of Physiology," vol. i, p. 452. 



