Personal and Scientific Nezvs. 399 
Professor Horace L. Wells, Yale University, chemist ; Profes- 
sor Edward L. Mark, Harvard University, biologist. 
Below is the list of papers read : 
"An estimate of the weight of the skeleton in the Sauro- 
poda, or in the Sauropodons Dinosaurs," Henry F. Osborn ; 
"New characters of the skulls of Carnivorous and Herbivor- 
ous Dinosaurs," Henry F. Osborn; "Models illustrating the 
evolution of the Amblypoda, also of the Dinosaur Diplodocus, 
together with the theory as to the habits of the Sauropoda," 
Henry F. Osborn; "Radioactivity of Thorium minerals," Geo. 
F. Barker; "The Law of Catalysis in concentrated -solutions," 
J. M. Crafts ; "The standardization of thermometric measure- 
ments," J. M. Crafts ; The Rumford Spectroheliograph of the 
■ Yerkes Observatory," George E. Hale; "The determination of 
standard right-ascensions free from the personal equation for 
star-magnitude" (with stereopticon illustrations), Lewis Boss; 
"On the semi-diurnal tide of the northern part of the Indian 
ocean," R. A. Harris, introduced by Cleveland Abbe; "The 
melting point of a simple glass," Arthur L. Day, introduced by 
G. F. Becker ; Biographical memoir of J. E. Holbrook," The- 
odore Gill ; "Biographical memoir of Matthew Carey Lea," 
George F. Barker; "Biographical memoir of Clarence King," 
S. F. Emmons; "Biographical memoir of A. A. Gould," Jeff- 
ries W^-man, read by W. H. Dall ; "Biographical memoir of 
James E. Keeler," Charles S. Hastings ; "The diffusion of va- 
por into nucleated air," Carl Barus; "Biographical memoir of 
Theodore Lyman," H. P. Bowditch ; "The nomenclature of the 
topography of the bottom of the oceans," Alexander Agassiz. 
Geological Society of Washington. At the meeting of 
Ma}^ 6th the following program was presented : "Correlation 
of the Potomac Formation in Maryland and Virginia," Lester 
F. Ward; "Pocono Rocks in the Allegheny Valley," M. R. 
Campbell ; "Age of the Mercer Group," David White. The 
special meeting of May 13th, 1903, was devoted to a considera- 
tion of "The Quantitative Classification of Igneous Rocks," 
continuing the discussion of the papers presented at the 140th 
meeting. An abstract of Dr. Mathews' paper is here given, 
which served as a basis for this discussion. 
Abstract of Dr. B. B. Mathczvs' Criticism of the Qitantitative 
Classification of Igneous Rocks. 
I. Strong points of the classification. 
I. Simplicity of the basal conceptions. There is no diffi- 
culty in grasping the basal conceptions which are applied with 
uniformity, and the rules for computation mav be followed 
without the introduction of personal equation. 
2. Sharpness of definition. The quantitative character of 
the classification produces sharpness in definition, leaves no ex- 
cuses for ambiguity, and enforces exact use of terms. The 
