REVIEWS. 
303 
very treacherous, consisting- of hot mud with a covering of sulphur about an 
inch in thickness, which in most places was about sufficient to bear a man’s 
weight. When this crust was broken, steam issued forth, strongly impreg- 
nated with sulphur. The clouds of steam, the roaring, the spluttering, and 
the splashing of these loathsome pits, the sickening smell and the desolate 
■country had somewhat of an awe-inspiring effect.” Mr. Shepherd gives 
some instructive details of the habits of the Icelandic birds, and he has given 
some happy sketches of Icelandic scenery, which have been chromo-litho- 
graphed in Hanhart’s best style. 
THE ELECTRIC TELEGRAPH.* 
T HE excellent and well-known treatise of Lardncr has been carefully 
revised and rewritten in accordance with the advance made of late 
years in the department of electrical physics. The task of editor was en- 
trusted to Mr. Edward Bright, and the publisher may congratulate himself 
on the selection. The book is in most respects a good, sound, intelligible, 
practical treatise on the electric telegraph. It deals with the elementary 
principles on which the application of electricity to telegraphic purposes is 
based, the modifications of the original apparatus employed in various 
■countries, the different forms of conducting cable, and finally of the uses — 
commercial, social, and political — to which the electric telegraph has been 
applied. There is one feature however, against which we must raise our 
voice : Electricity is described in the language of the popular lecturer as 
a 11 subtle fluid.” This is extremely objectionable, and the more so as the 
editor is fully aware that the modern view of the force is opposed to such 
a mode of expression. Mr. Bright urges that the term fluid is the most 
convenient for the purpose of explaining electrical phenomena. In this 
we totally differ from him. In the first place the term so applied is erro- 
neous, and in the second, the word wave would answer every purpose which 
is served by fluid. For the merely practical electrician, there may be no 
harm in employing the word fluid, but it must be remembered that Dr. 
Lardner’s work as the chief popular treatise on the telegraph, goes into our 
schools and families, and is thus calculated to do a certain amount of mischief. 
Mr. Bright may not be familiar with the history of other sciences, but if he 
be, he must know how injurious to the progress of knowledge it is to 
hamper a branch of science with a term implying an hypothesis which has 
not one tittle of evidence to support it Such expressions as “ vital force ” and 
“electric fluid,” and such like, are stumbling-blocks to the progressive student. 
We have little doubt that had it not been for the adoption of such techni- 
calities as electric-fluid, tonicity, and irritability, the action of the muscles 
* The “Electric Telegraph.” By Dr. Lardner. A new edition revised 
and rewritten. By E. B. Bright, F.R.A.S. Secretary of the British and 
Irish Magnetic Telegraph Company. London : James "Walton, 18G7. 
VOL. VI. — NO. XXIV. Z 
