258 Chronicles of Science. [April, 
the name of Dana that we are loth to notice an alleged charge of 
plagiarism recently brought against him in connection with his 
views on the relation between crystalline form and chemical compo- 
sition.* Professor Hinrichs, of lowa, alleges that some of the ideas 
expressed in the papers on this subject had their source in a 
memoir of his own recently written on “ Atom Mechanics.” It is 
needless to say that Dr. Dana refutes this charge triumphantly, 
and shows it to be utterly groundless. By the way, the “ Atom 
Mechanics” just noticed contains some curious arguments which 
will at least amuse the reader if they fail to convince him. The 
professor believes in the chemical unity of matter, and recognizes 
the existence of only one true element, one all-pervading form of 
primitive matter, or Urstoff, which forms the basis of everything 
material, and which he introduces to us under the name of Pantogen. 
The “ Atom Mechanics” may, however, be commended to the reader, 
if only for its curiosities of style and elegance of illustration. For 
example, wishing to express the impossibility of basing a minera- 
logical classification upon crystalline form, the professor tells us 
that “One might quite as well classify asses according to the 
lengths of their caudal appendages expressed in centimetres, as 
minerals by their systems of crystallization !” 
Availing himself of some specimens of ruby, or red corundum, 
exhibited in the Colonial Department of the Paris Exhibition, M. 
Jannettaz has studied the nature of the colourmg matter of this 
gem. He found that on exposure to heat the red colour rapidly 
gave place to a bright green, but that on cooling, the mineral 
resumed its original tint. Previous experiments on the spinel- 
ruby had shown that this gem when heated exhibits precisely the 
same behaviour. 
Analyses of between 30 and 40 different coals from various 
localities in Prussia, together with a comparison of their respective 
calorific powers, have been published by M. Mene,t who obtained 
his specimens from the Paris Exhibition. The analyst throws his 
results into a tabular form, and, trusting to their intrinsic value, 
leaves them without comment. 
In the clefts of some of the Lower Silurian sandstones of 
Bohemia, a couple of new minerals have lately been discovered, 
and described by Von Zepharovich.§ Both of these are hydrous 
phosphates of alumina, closely related to the well-known species 
Wavellite. One of them is to be called Barrandite, in compliment 
to the zealous geologist of Bohemia, Joachim Barrande; and the 
* See ‘Quart. Journ. of Science,’ Jan. 1868, p. 103. 
+ ‘ Observations minéralogiques sur quelques minéraux de I’Inde, et en parti- 
culier sur la nature de leur coloration.” Bull. de la Soc. Géol. de France. XXIV. 
No. 5, p. 682. t ‘Comptes Rendus,’ LXV. No. 20, p. 807. 
§ Sitzungsb. d. k. Akad, Wiss, Bd. LYL, p. 19. 
