166 



Dr. J. S. Lombard on 



[Mar. 7, 



Two resistances were inserted in the circuit for two different sets of 

 readings, in the first case 1*1 ohm of total resistance, in the other 2*72. 



Table VI refers to these experiments, the curve marked A in the 

 Diagram V being that due to the first, B being that due to the second. 

 It will be noticed that practically the curve becomes a straight line, 

 or, in other words, the electromotive force increases directly as the 

 number of revolutions of the armature, a result which might have 

 been expected theoretically. It will also be seen that the current for 

 any given number of revolutions varies inversely as the resistance in 

 circuit, or, in other words, that the electromotive force for a given 

 number of revolutions is constant. 



In any results, therefore, which are given descriptive of the light 

 produced by any machine, the following should be noted : — 



Number of revolutions of armature ; 

 Resistance in circuit ; 

 Horse-power expended ; 

 Colour of light measured ; 

 Electromotive forces. 



together with the size of the carbons employed, and other obvious 

 details. 



II. " Experimental Researches on the Temperature of the 

 Head." By J. S. Lombard, M.D., formerly Assistant- Pro- 

 fessor of Physiology in Harvard University, U.S. Com- 

 municated by H. Charlton Bastian, M.D., F.R.S., 

 Professor of Pathological Anatomy in University College, 

 London. 



(Abstract.) 



The present communication forms an abstract of the first portion 

 of a series of investigations having the following primary objects in 

 view : — 



1st. To find out, as far as possible, the normal relative temperatures 

 of different portions of the surface of the head, when the brain is 

 comparatively inactive. 



2nd. To study the effect of different mental states upon the 

 different portions of the surface of the head previously examined in 

 the condition of comparative cerebral inactivity. 



The ultimate objects were two-fold; namely : — 



1st. To furnish, if possible, some reliable data as a starting point, 



