140 
SCIENCE. 
BOOKS RECEIVED. 
A Physical Treatise on Electricity and Mag- 
netism. By J. E. H. Gordon, B. A., Camb., Assist- 
ant Secretary of the British Association. In two 
volumes. [London : Sampson Low, Marston. Searle 
and Rivington. 1880. 
One of our correspondents calls attention to what he 
considers a breach of privilege on the oart of a publish- 
ing house, which affixes the date 1880 to a scientific text- 
book which does not mention the telephone or moto- 
graph. If this omission be a sin it is simply a sin of 
omission ; but quite different is it in the case of Mr. J. E. 
H. Gordon, an English compiler of a work on electricity 
and magnetism, in two volumes, which has come to us, 
with a flourish of trumpets, across the Atlantic. This 
book, which gives many pages (we will not say, however, 
too many, as the subject is an interesting one) to De La 
Rue’s beautiful experiments, and eighteen pages to Mr. 
Crook’s etherial and radiant speculations with Mr. 
Gimingham’s pretty tubes, only condescends to notice 
the Bell telephone in one brief page, and entirely ignores 
the existence of Edison’s carbon telephone; although he 
recognizes the principle of the latter in Hughes’ micro- 
phone, to which he gives great credit in another page. 
Aside from the unpardonable negligence evinced in this 
want of literary balance, which shows Mr. Gordon’s in- 
capacity as a book compiler, we here have a recurrence 
of an indignity unworthy of an Englishman. Mr. Gor- 
don (who is an Assistant Secretary of the British Asso- 
ciation) knows, or ought to know, that Mr. Preece exhib- 
ited an Edison musical telephone to the Association at 
their Plymouth meeting in 1877 ; and also that Edison’s 
agent in London showed Mr. Hughes the carbon button 
and its properties in a telephone, three weeks before Mr. 
Hughes picked up the eliminated defects of the button 
as the principle of the microphone. 
It does seem as if this ignoring the great services of 
the American Edison is but a part of a scientific con- 
spiracy to falsify history. Where is the tasimeter, the 
most delicate electrical instrument for the measurement 
of radiant energy known to science ? Where the moto- 
graph, that inexplicable wonder, which a telegraph com- 
pany (more appreciative than Mr. Gordon) thought worth 
a hundred thousand dollars, the price they offered and 
paid for it? Where are their descriptions to be found in 
Mr. J. E. H. Gordon’s Physical Treatise on Electricity 
and Magnetism ? He does not deign to pen one line on 
the subject. This is either ignorance or folly ; let Mr. 
Gordon accept which horn of the dilemma he thinks 
better. 
However, considering the hasty manner in which the 
text of this book is thrown together, it can scarcely pass 
into currency, except as a beautifully illustrated catalogue 
of inventions and discoveries in which Mr. Gordon took 
no part. In this compilation (without reference, let it be 
distinctly understood, to the distinguished authors whose 
works are woven in without decent order or proportion), 
Mr. Edison shines by his absence. 
The book cannot yet be purchased here, as the Amer- 
ican buyers of the copyright are keeping it for the fall 
trade. We regret their connection with it, for what 
popularity can be expected, in this country, for a work on 
electricity that ignores the existence of Henry, Morse 
and Edison ? 
Manual of Hydraulic Mining for the use of 
the Practical Miner. By T. F. Van Wagenen, 
E. M., New York, D. Van Nostrand, 1880. 
Of all the problems presented to the mining engineer, 
there is none more important, nor simpler, than that con- 
tained in the subject of hydraulic mining of gold. It is 
only necessary to be sure of the premises and the results 
may be considered certain. There are, really, but two 
questions involved, water to move the soil, and place to put 
it in. If these conditions are fulfilled, it is not difficult to 
predict success to those who have but fair promise of 
paying ground. Once we know where is the dump- 
ing ground, how high the fall, and what the grade 
at command for sluicing boxes, all that has to be done is 
to bring water to the highest point above the workings ; 
which, of course, presupposes it has been lead from the 
source to the place of fall on the least grade consistent 
with a sure and economical supply. 
Much of the brain and sinew of the working classes 
in the far West has taken to this class of mining, as 
offering the most enduring profit and employment ; 
but hydraulic mining requires something else besides 
mere will and muscle. For its successful application 
a certain knowledge of figures, rather than of miner- 
alogy, is requisite. These hardy men do not always 
possess such knowledge, and for their instruction, Mr. 
Van Wagenen has written a little manual which will 
be read, studied and understood by many a practical 
miner. 
The book can serve as a model for writers who have 
something valuable to say, and who wish to speak to 
men who have no desire to waste time in hunting for the 
truth. 
PHYSICAL NOTES. 
The new electro-dynamic law of Clausius is receiving the 
deepest attention from the first electricians and mathema- 
ticians of Europe. The fundamental character of all his 
work and the acknowledged preeminence of his views, imme- 
diately demand an early investigation at the hands of his 
compeers. Already have Lorberg, Delsaulx, Frolich and 
others submitted this law to rigid analysis. 
This new law of Clausius was advanced by the distin- 
guished author only after finding himself unable to reconcile 
the two laws of Weber and Rieman with that simplicity which 
overwhelmingly addresses itself to our reason ; and because 
they seem too complicated to be used as explanatory of these 
molecular currents so felicitously employed by Ampere in 
his theory of magnetism. These laws of Rieman and Weber 
require us to believe in the existence of two equal and oppo- 
site currents as originating all electrical action. In another 
essential point, Clausius (Annalen der Physic und Chemic 
X., 4, p. 609), finds himself compelled to differ from Rieman 
and Weber. They assume a relative motion between the 
electrified particles. Rieman using the word in its ordinary 
acceptation, according to which the difference of the compo- 
nents of velocity of the two electrical particles is made to 
represent the components of velocity of the relative motion ; 
and Weber referring the relative motion to the mutual ad- 
vance and retreat of the particles. Clausius rejects this 
method, which would confine one in the consideration of 
the subject to relative motion, and treats of both individual 
motions of the particles in their action on each other. 
In the same number of the Annalen is an article by Herr 
Budde, on the laws of Clausius, in which, as an adherent of 
the theory, he exposes the fallacy of Frolicli’s interpretation. 
The contrary effects of sunlight in relation to certain 
chemical compounds, is noted by T. P. Blunt {Analyst. 
1880, 79-81), who finds that an oxalic acid solution exposed 
to the light is rapidly decomposed, which is not the case in 
the dark. If this observation of Mr. Blunt is substantiated 
the use of that valuable re-agent in stoichiometry, where it 
serves as a basis for standardizing, will have to be re- 
stricted. From the ease with which oxalic acid is dried 
and weighed, and its non-corrosive nature, it has been con- 
sidered almost invaluable in the working laboratory. 
Mr. Blunt, on the other hand, finds that ferrous iodide 
requires the light in order to prevent decomposition. 
Does not this anomalous action of light point to a mechan- 
ical association and dissociation of molecules, analagous to 
that separation of tangible bodies effected by sound, as 
seen in Chladni figures? 
