506 
PHILOSOPHICAL SOCIETY OF WASHINGTON. 
Thus I propose the law that an alloy can be formed out of the constituents 
at a temperature above the melting point of the alloy, although it be far below 
that of any constituent, with no ( appreciable) pressure. 
The extended verification of this law, as well as the electrical and ther¬ 
mal phenomena associated therewith, will be the subject of a work which 
I hope soon to undertake and carry through. 
An abstract of this paper was also published in Science, vol. 
11, pp. 99, 100, Mar. 2, 1888. 
315th Meeting. March 3, 1888. 
The President in the chair. 
Thirty-two members and guests present. 
Announcement was made of the election to membership of 
Andrew Braid and Arthur Keith. 
The following papers were read: 
On the Determination of Atomic Weights, by Mr. F. W. Clarke. 
Notes on the Drift north of Lake Ontario, by Mr. J. W. Spencer. 
[Abstract.] 
Amongst the deposits of the later Pleistocene period there is a well- 
stratified, hardened brown clay, charged with pebbles which are more or 
less glaciated, resting upon the typical blue bowlder clay north of Toronto. 
In the Canadian classification of the Pleistocene deposits there is no place 
for this deposit. Indeed, all of the stratified deposits of this region need 
revision, in the light of the progress that has been made in surface geology 
during the last twenty years. Thus, the Saugeen clay is resolvable into 
three series. The relation of all the clays to the older beaches require 
special study, as some of them may represent the deep-water deposits of 
the Beach epoch, while some of the' later beaches rest upon such clays. 
Around the head of Georgian bay there are ridges in the form of moraines, 
similar to those about the other great lakes, reaching to the height of 
1,300 to 1,400 feet above the sea. From the face of the Niagara escarp¬ 
ment—between Georgian bay and Lake Ontario—there extends for over 
a hundred miles, to near Belleville, a broad zone of from eight to twenty 
miles in width, covered with drift ridges, composed of stony clay below 
and frequently stratified clay or sand above, having an elevation of'1,100 
to 1,200 feet above the sea, with occasional reductions to only 900 feet. 
These “ Oak Hills or Kidges ” rise from 300 to 500 feet above the flat Paleo¬ 
zoic country to the north. The stones in the clay are often glaciated 
fragments of limestone, with only a small proportion of crystalline pebbles 
