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XXXIV. Notices respecting New Books. 



On Aynmal Electricity ; being an Abstract of the Discoveries o/Emil 

 Du Bois-Reymond, Member of the Academy of Sciences, Berlin, SfC. 

 Edited by H. Bence Jones, M.D., F.R.S., Physician to St. George's 

 Hospital. London : John Churchill, Princes Street, Soho. 



WE have long wished to see an English abstract of the researches 

 of M. du Bois-Reymond, and the book before us answers to 

 the wish. It commences with a brief but extremely interesting historic 

 introduction, in which, as might be expected, Galvani and Volta 

 are the principal figures. Comparing these two celebrated men, the 

 author oliservcs, — 



" No one who wishes to judge impartially of the scientific history 

 of these times and of its leaders, -will consider Galvani and Volta as 

 equals, or deny the vast superiority of the latter over all his oppo- 

 nents or fellow- workers, more especially over those of the Bologna 

 school. We shall scarcely again find in one man gifts so rich and so 

 calculated for research as were combined in Volta. He possessed 

 that ' incomprehensible talent,' as Dove has called it, for separating 

 the essential from the immaterial in complicated phsenomena ; that 

 boldness of invention which must precede experiment, controlled by 

 the most strict and cautious mode of manipulation ; that unremitting 

 attention which allows no circumstance to pass unnoticed ; lastly, 

 with so much acuteness, so much simplicity, so much grandeur of 

 conception, combined with such depth of thought, he had a hand 

 which was the hand of a workman." 



The progress of discovery in this department of science is sketched, 

 and the author afterwards passes on to describe his instruments and 

 manner of experiment. "We have a valua1)le and instructive chapter 

 on the improved galvanometer. The helix of the larger instrument 

 used by the author consists of the astonishing length of 3" 17 English 

 miles of copper wire in 24,160 coils ! It would be difficult, if not im- 

 possible, without drawings to give an intelligible description of the 

 author's mode of experiment. Every precaution which experience 

 could suggest, and the most refined manual dexterity could apply, 

 has been taken to secure accuracy, and rescue the results from inci- 

 dental disturbances. The main feature in the experiments is, that 

 the contact of metals with muscle or nerve, or with each other, is as 

 much as possible avoided, connexion being established by cushions 

 of bibulous paper moistened with a saturated solution of salt and 

 water. Nor is contact with even these permitted, lest an irritating 

 action should be exerted upon the tissue ; the cushions are protected 

 by a cover of ])ig's bladder with a little albumen spread over it, and 

 upon or against this the tissue to be examined is laid. 



The great law established by the author, and of which the so-called 

 frog current, together with the various i)hsenomena observed by 

 M. Mattcucci, are to be regarded as particular manifestations, more 

 or less con)])licated, is one of extreme simplicity. Let us suppose 

 the circuit all complete with the exception of one small gap, at each 

 side of which stands a cushion of bibulous paper moistened and pro- 



