Literm^y Notices. 157 



dicularly, one up and the other down, so that the metallic balls on 

 their other extremities may be at an adjustible distance from each' 

 other. The apparatus is charged by placing a sheet of paper that 

 has been well dried at the fire and electrified by friction, very near, 

 but not in contact with the disc, opposite to one of the pointed 

 collectors, but not at the same side of the disc. On turning the 

 machine, a luminous jet will pass between the balls. If the disc 

 is covered with gum lac, and sheets of paper oppositely electrified 

 are placed opposite the points of the collectors — one sheet being op- 

 posite to each collector — the intensity and duration of the effects 

 obtained will be greatly increased. When the experiment is care- 

 fully made, sparks, five centimetres in length, will pass between the 

 balls, and a Leyden jar, the coatings of which are connected, 

 respectively, with the latter, will be charged with great rapidity. 



LITERARY NOTICES. 



Diarrhcea and Cholera ; their Nature, Origin, and Treatment, 

 through the Agency of the Nervous System. By John Chapman, 

 M.D., M.R.C.P., M.R.C.S. Second Edition, enlarged. (Triibner 

 and Co.) — We have on a former occasion mentioned Dr. Chapman's 

 treatment of cholera by the application of ice-bags to the spine. He 

 founds this practice upon a theory which is at any rate plausible ; and 

 as medical treatment of this terrible disease has in the main proved 

 a lamentable failure, he is entitled to make a strong demand for the 

 trial of his plans. Diarrhoea and cholera he regards as substantially 

 the same disease, arising from over-excitement of nervous centres, 

 and remediable by diminishing the action of the particular nerves 

 supposed to be over-stimulated. He is as unable as other members 

 of his profession to give us any intelligible account of how and why 

 excessive heat, great changes of temperature, impure water, etc., 

 combine to generate cholera in some seasons more than others ; 

 but he has brought together a considerable mass of information 

 which tends to increase disbelief in the value of the ordinary treat- 

 ment, if it does act with equal power in creating faith in ice. Opium, 

 stimulants, calomel, and sulphuric acid are among the agents which 

 Dr. Chapman considers positively mischievous. The effect of the 

 ice treatment applied to the spine only is illustrated by numerous 

 cases, and when accompanied by warm drinks, is affirmed to have 

 been highly successful. The question is, has Mr. Chapman, in his 

 zeal as a supposed discoverer, exaggerated the merits of his nos- 

 trum ? We look to the medical world to answer ^this query by 

 authentic cases, and a fair comparison of different methods. If Dr. 

 Chapman is wrong, let his theory go the way to oblivion which 

 previous errors have traversed — if right, let society have the 

 benefit of it, whatever may be its consequences to medical 

 orthodoxies. 



Researches on Solar Pnrsics. By Warren De La Rue, Esq., 



