8io THE POPULAR SCIENCE MONTHLY. 



This inhibition may he brought about by nervous impulses coming 

 from certain sensory nerves^ as those of sights touchy hearing. 



It may also be brought about by impulses or changes arising in the 

 cortex itself. 



The inhibited cortex, and probably also inhibited lower centers of 

 the brain, send out inhibitory impulses to all other parts of the central 

 nervous system, so that the mesmerized man or animal gradually passes 

 into a state of torpor, or even of complete anaesthesia. 



The phenomena of the excitable stage of mesmerism are proximately 

 determined by the possibility of exciting any particular center alone, 

 without exciting at the same time other centers by which its activity is 

 normally controlled. In lower animals this stage is less marked in 

 consequence of a greater interdependence of the various parts of the 

 central nervous system. 



I would expressly state that I regard this theory only as provisional. 

 Further, I am quite conscious that it is very imperfect. A complete 

 explanation of the phenomena of mesmerism and of its allied states 

 can only be given when we have a complete knowledge of the struct- 

 ure and functions of all parts of the central nervous system. But I 

 have not much doubt that the explanation of the main features of 

 mesmerism will be found when we are able to answer the question, 

 What is inhibition ? And it is some comfort to think that the answer 

 awaits us in the comparatively simple nervous system of the lower 

 animals. I would not be understood to mean that variation of blood- 

 supply and various other events are of no influence in producing mes- 

 meric phenomena ; I think, however, that these events are of secondary 

 importance only. 



PEOTECTIOK AGAINST LIGHTNING. 

 II. 



IN the year 1875 the Meteorological Society of London was moved to 

 follow the lead of the French meteorologists in reference to light- 

 ning-conductors, and to appoint a Lightning- Rod Committee. From 

 the report made to the society by the council in the following year, it 

 appears that the objects contemplated in this action were " an inves- 

 tigation and record of accidents from lightning, an inquiry into the 

 principles involved in the protection of buildings, the diffusion of exact 

 information regarding the best form and arrangement for lightning- 

 conductors, and the consideration of all phenomena connected with 

 atmospheric electricity."* It is obvious that in its first conception 

 this committee was intended to be essentially one of investigation and 



* See " Quarterly Journal of the Meteorological Society," vol. iii, p. 75. 



