JUNE 6, 1884.] 
magnesian salts in sea-water, was the source 
of serpentine, pyroxene, etc. ‘The gradual re- 
moval by solution from below, of vast quantities 
of material, and the resulting contraction of the 
primitive stratum, caused the universal corru- 
gations of the upper acidic or gneissic layer. 
From the undissolved basic residual portion 
have come such eruptive rocks as melaphyres 
- and basalts, while granitic and trachytie rocks 
are softened and displaced portions of the 
acidic or secondary layer. The author has 
developed at length this hypothesis, which, 
according to him, affords a satisfactory expla- 
nation of many hitherto unsolved problems in 
geology. 
In a paper on the density and the thermal 
expansion of aqueous solutions of sulphate 
of copper, Prof. J. G. MacGregor gave an 
account of extended observations made to 
determine the density of solutions of differ- 
ent degrees of concentration, and at different 
temperatures. As a general result of the ex- 
periments, it is shown, 1°, that the rate of vari- 
ation of density with temperature in all cases 
increases with the temperature and with the 
degree of concentration ; 2°, that at low tem- 
peratures (below about 25° C.) the rate of 
change of density with temperature is for all 
solutions greater than the same rate for water ; 
3°, that the difference between these rates 
diminishes as the temperature increases; and, 
4°, that for most solutions (probably for all) 
these rates are, at sufficiently high temperatures 
(30°-50°), the same as for water, i.e., the 
thermal expansion of solutions is the same as 
that of water at these temperatures. The 
experiments also substantiate a result formerly 
obtained by Professor Ewing and the author, 
that very weak solutions of this salt have a 
volume smaller than that of the amount of 
water which they contain. 
Prof. E. Haanel gave a continuation of his 
paper, presented to the society last year, on 
blowpipe re-actions on plaster-of-paris tablets, 
in which he described the effect of treating 
copper with hydrobromic acid, and iron with 
hydriodic acid, and showed how to distinguish 
between selenium and mercury. He described 
also the coatings per se, for the above tablets, 
for selenium, tiemannite, arsenic, silver, alloys 
of bismuth, lead, and antimony with silver, 
galena, orpiment, realgar, mercury, tellurium, 
earbon, cadmium, and gold. 
The same author gave a description of ap- 
paratus for distinguishing flame-coloring con- 
stituents when occurring together in an assay. 
The apparatus consists of a spectacle-frame, 
furnished for the left eye with plain colorless 
SCIENCE. 
675 
glass, and, for the right eye, with four glasses, 
—red, green, violet, and blue. These glasses 
revolve on an axis, and can be brought, either 
separately or in any combination, before the 
right eye of the operator. 
Prof. N. F. Dupuis showed how to develop 
by simple algebraical methods certain functions 
ordinarily developed by the aid of the calculus. 
Prof. E. J. Chapman described a series of 
analyses of magnetic and other iron ores from 
samples obtained by him personally from vari- 
ous parts of Ontario. The geological condi- 
tions of the deposits were also briefly given. 
In the geological and biological section, 
Dr. A. R. C. Selwyn gave an account of his 
observations, in 1883, on the geology of a part 
of the north shore of Lake Superior, in which 
he considered he was able to show that the 
creat masses of columnar trap which form 
the summit of Thunder Cape, Pie Island, and 
McKay’s Mountain, were not part of a ‘ crown- 
ing overflow,’ as they have been described to 
be, and newer than the Keweenawan series, but 
that they are contemporaneous with the black 
slaty shales of the Animikie group, which 
immediately and conformably underlie them. 
Professor George Lawson presented a re- 
vision of the Canadian Ranunculaceae. The 
author referred to his monograph of Ranuncu- 
laceae, published in 1870, to the extensive col- 
lections that had been subsequently made, and 
to works published upon the North-American 
flora, — all of which enabled a fuller and more 
accurate description of Canadian ranunculace- 
ous plants to be given now than was possible 
when the previous paper was prepared. The 
greater precision given to recent observation 
had also enabled the geographical range of 
these plants to be stated more fully. The 
striking diversity of modification in the form, 
number, and arrangement of the several parts 
of the flower and of the fruit, in the several gen- 
era, was pointed out. The number of Cana- 
dian species is seventy-eight, and of varieties 
eighteen. 
Dr. T. Sterry Hunt presented a second part 
of his essay on the Taconic question in geol- 
ogy, in which he endeavored to show in the 
first place, more fully than has yet been done, 
the relations of the Taconian or lower Taconic 
series of stratified rocks to the succeeding 
Cambrian, or upper Taconic, which some geol- 
ogists have confounded with the Taconian. 
In this connection is given a critical discussion 
of the studies of Perry, Marcou, and others, 
and the opinions of Dana, as regards the Cam- 
brian of the Appalachian region of North 
America. In the second place is considered 
