J. W. Dawson on Fossils of the Laurentian. 231 
the same as the law that is derived from the consideration of the 
relative attraction of the two bodies revolving about their com- 
mon centre of gravity.” That such would be the case might 
have been reasonably expected from the dependent connection 
of rotation and revolution with gravity. 
was therefore led to believe that the daily lunar tides might 
be indicated by the same expression as the weekly lunar and 
daily rotation tides. On investigation, I find that such is indeed 
the case. If M is the barometric mean for any gues day and 
Place, and @ is the moon’s altitude, the lunar tide may be ex- 
pressed by MC (sin 9cos4), C being a constant to be determined 
for each station. 
The rationale of Mr. Flaugergues’s second and third inferences 
thus becomes evident; the phenomena of ocean tides are con- 
nected with those of the air, which, being subject to fewer extra- 
neous disturbing influences, can therefore be more easily inves- 
tigated; and the long-suspected obedience of the principal me- 
teorological changes to fixed mathematical laws is at lengt 
ted 
o 
demonstrated. 
Art, XXVI.—Extracts from the Address of Dr. J. W. Dawson, 
President of the Natural History Society of Montreal, at its annual 
meeting, May 18, 1864.’ 
Fossils of the Laurentian, 
and much older than any rocks known to contain ossils. € 
oldest remai ivi in til this discovery, had been 
test remains of living beings, un a peiedial ie ate. 
2 From the Canadian Naturalist, 1864, 
