226 Scientific Intelligence. 
my mind, one of Dr. Emmons’s greatest services to the cause 
of science was his recognition of the great stratigraphical 
break running east of the Hudson River by which the Primor- 
dial rocks were made to stand above those at the top of the 
Lower Silurian, and his advocacy of it in spite of the adverse 
paleontological determinations of Professor Hall, who referred 
the whole at first to the Hudson River group, and subsequently, 
at least in part, to the Quebec. Dr. Emmons’s pronounce 
antagonism to the Hudson River doctrine grew, in this case at 
any rate, out of his appreciation of fundamental differences; and 
_ for this signally good work, notwithstanding the failure of his 
favorite system, he should ever receive, it seems to me, the 
grateful recognition of all workers in the department. 
New York, February 5, 1880. 
SCIENTIFIC INTELLIGENCE. 
I. CHEMISTRY AND PuHysiIcs. 
pera- 
tion, this boat contained a rod of solid coherent platinum sponge, 
having the form of the vessel. Removed with care, its weight 
was almost precisely that calculated from the PtCl,, No trace 
of sublimed or crystallized platinum could be detected. As to 
ee Be 
2. On the Action of Phosgene gas on Ammonia.—¥EnTON 
has examined the white amorphous substance which is produced 
when phosgene gas (COCI,) acts upon ammonia, with a view t0 
ascertain whether the urea contained in it is the ordinary form of 
this body or an isomer of it. For the preparation, the two thor 
oughly dried gases were brought together in large flasks, the 
phosgene being prepared by passing carbonous oxide through 
* This Journal, III, xix, 65, Jan,, 1880. 
