Geology and Mineralogy. 463 
in suspension in the form of mud, are extremely interesting, and 
Mr. Reade deduced from them that the minimum amount of tim 
which must have elapsed since the first sedimentary rocks we 
know of were laid down is, in round numbers, 500 millions of 
years, thus supporting the views of Lyell, Hutton, and other great 
geologists, as to the immense age of the world.—Nature, Oct. 26. 
8. Mallet’s Theory of Voleanic Energy.—The paper of Prof. 
Mallet upon volcanic energy, which was translated into German 
by Prof. A. von Lasaulx, has been somewhat severely criticized in 
the Gottingen Gelehrte Anzeige by O. Lang. This criticism has 
recently been fully answered by Prof. Lasaulx. He gives a satis- 
factory demonstration of the mathematical formula referred to 
a , that by which Mallet proves that a crushing of the 
9, ‘p 
The American Association for the Advancement of Science, at its 
Session on the 25th of August last, umanimously adopted the fol- 
lowing resolution :— 
esolved, That a Committee of the Association be appointed by 
the Chair to consider the propriety of holding an International 
Congress of Geologists at Paris, during the International Exhibi- 
tion in 1878, for the purpose of getting together comparative col- 
lections, maps and sections, and for the settling of many obscure 
points relating to geological classification and nomenclature. And 
e sa 
t of Prof. William B. Rogers, Messrs. James Hall, J. W. Daw- 
son, J. S. Newberry, T. Sterry Hunt, C. 
ch and German, and to be distributed to geologists ee da 
out the world, asking their codperation in this great work “i an 
International Geological Exhibition and an International 0B. 
‘cal Congress to be held at Paris in 1878; the precise date of the 
gress to be subsequently fixed. ‘ 
This cireular fected: with reference to the objects of the 
