Nickel and Copper of Sudbury. 69 
that they have been brought up by the latter. 3rd, As segregated 
veins which may have been filled subsequently to the intrusion 
which brought up the more massive deposits. These veins are not 
very common, although certain portions of the more massive 
deposits may have been dissolved out and redeposited along cer- 
tain faults and fissures. 
Assays made for the Canadian Copper Company, by Mr. F. L. 
Sperry, the chemist, show a range in the percentage of nickel from 
1.12 to 4.21 per cent., with an average of 2.38 per cent., while the 
copper varied from 4.03 to 9.98 per cent., with an average of 6.44 
per cent. Mr. Hoffmann, of the Geological Survey, assayed four 
samples which showed the nickel contents to vary from 1.95 to 
3.10 per cent., with an average of 2.25 per cent. The metallurgical 
treatment commences at the roast, where the ore is piled in rec- 
tangular heaps on previously laid cordwood and roasted for fifty to 
seventy days, and when thoroughly done should contain about 7 
or 8 percent. of sulphur. It is then smelted in a very perfect 
water-jacketed furnace, the resulting product, or “matte,” contain- 
ing about 27 per cent, copper and 14 per cent. nickel. This is then 
packed in barrels and shipped to various refiners in the United 
States or Europe, according to their respective bids. 
The paper in question is the most succinct and best report we 
have as yet seen upon the ores and geology of the region about 
Sudbury, and no one interested in the geological and mineralogical 
problems involved, as well as the metallurgical points with which 
it deals, should be without it. 
A. M. Amt. 
ERosion IN THE DusERT OF THE LirrLE CoLoRADO. 
In No. 3 of “ North American Fauna,” recently published by the 
United States Department of Agriculture (1890-1), Dr. C. Hart 
Merriam, in addition to an immense amount of most valuable 
information on the botany and zoology of Arizona and Idaho, gives 
a graphic description of the peculiar erosion topography of the 
Desert area, as well as an account of several cloud-bursts which he 
witnessed while travelling in that almost unknown region. As 
these cloud-bursts, although having a very remarkable effect on 
the character of the erosion, occur but rarely and have been but 
very seldom described by competent observers, the following ex- 
tracts from Dr. Merriam’s reports, which are of especial interest, are 
here reproduced : 
The Desert of the Little Colorado, sometimes known as the 
* Painted Desert,” is a great basin about 1,000 meters (3,300 feet) 
