386 J. L. Smith—Daubrée’s Experimental Geology. 
‘ 
metallic silver used, and also of the bromide of antimony, 
which is the basis of this atomic weight investigation. By 
comparing 6 6 and b 7 with 4 4 and 6 5 respectively, we obtain 
the following data :— 
1. 2°9749 gram of silver gave 5°1782 gram bromide of silver. 
9. 2°4745 ““ 6c “6 4°3076 “c “ “ 
Hence it follows that, as shown by these experiments, the 
proportions of the silver to the bromine were respectively :— 
1. 108°00 Silver to 79°99 Bromine. 
%. ape0o:. .“.. ©. 8O01 sae 
Mean value, 108700 “ “ 80°00 ai 
This is the ratio of the atomic weight of silver to that of 
bromine, and corresponds to the second decimal place with the 
determinations of Stas as well as with those of Dumas. 
n conclusion it gives us pleasure to express our obligations 
to Mr. G. De N. Hough and Mr. G. M. Hyams, two students of 
this laboratory, who have greatly aided us in the experimental 
work of this investigation. 
Cosmical 
Art, LIL—Daubrée’s Experimental Geology: Part I, Expert- 7 
mental Study of Meteorites with reference to certain 
Phenomena; noticed by J. LawRENCE SMITH. 
Etudes Synthétiques de Geologie Expérimentale; par A. Daubrée, Deuxiéme 
partie—application de la methode expérimentale a l’étude de divers phénoménes 
cosmologigues 
THE first part of Professor Daubrée’s valuable work on 
experimental geology appeared several months, since.* The 
second part, embracing about 850 pages, is exclusively devoted 
to an experimental study of the structure and genesis of 
meteoric minerals, and to the bearing of the facts on the constl- 
tution of the universe. 
The first chapter of the part before us is devoted to the 
study of the phenomena attending the fall of Aerolites and to 
onths, August and November, remarkable for showers of 
is important that this fact should be clearly stated and reiter- 
ated, since many scientists are disposed to connect these two 
classes of phenomena; until shooting stars and meteoric stones 
are treated of wholly independently, no approach will be made 
to a correct theory in regard to the origin of the latter. 
* This Journal, August, 1879, p. 150. 
i Bien 
