SCIENCE. 
227 
per, not so much in older rocks as iti later formations. 
Demonstration : 
I. PARAMAGNETIC METALS AND THEIR ORES. 
1. Iron. — A considerable portion of this metal as 
magnetite, both in the United States and in Scandi- 
navia, is magnetic, possessing polarity. Specimens 
from Magnet Core, Ark., and from near Pilot Knob, 
Missouri, in the United States, and from Dannemora, 
in Sweden, present this character very strongly. 
(a) Nearly all the important iron of the United 
States (as can be ascertained from Dana’s Mineralogy, 
or readily seen by inspecting Map No. VIII in Cor- 
nell’s Phys. Geogr.) occupies a north and south belt, 
between the meridians of 77 0 and 91 0 long. W. of Gr.) 
extending north and south from Lake Superior to 
Alabama, average lat., say 40 02 . On the opposite 
side of the globe, this belt, prolonged in a great cir- 
cle, will include the main iron belt of Asia. 
(b) The iron of Europe is in a belt about (20) 
twenty degrees or nearly 800 3 statute miles in width, 
namely from long. 5° W. to long. 15° E., extending 
north and south from Scandinavia to Tunis: thus 
being about 90° distant from the American-Asiatic 
belt. 
(c) The only other iron laid down in Cornell is 
in a belt from near the Urals to a deposit in Persia, 
half way between the European and the Central Asi- 
atic iron belt, or about 45° distant from each of 
these. 
{d) Dana mentions some iron in the region of 
San Francisco, which would be about 45° west of the 
Pennsylvania portion of the main United States belt. 
2. Manga?iese. — The localities given by Dana for 
this metal would fall almost, if not entirely, within the 
iron belts of North America and Europe : showing a 
similar tendency to assume a paramagnetic direction. 
3. Platinum. — The chief localities of platinum, as 
given in Dr. Dana’s Manual of Mineralogy ; namely, 
the Ural Mountains and North Granada, South Ame- 
rica, as well as Canada and North Carolina, where 
traces have been found, fall within the United States 
iron belt. Borneo and places in Minas Geraes, Bra- 
zil, where some platinum has been taken out, are very 
slightly east of the above-named belt. 
4. Nickel and Cobalt. — Ores of these metals are 
found, according to Dana, in Cornwall, Sweden, Nor- 
way, France, Saxony and the United States (Missouri, 
North Carolina, Pennsylvania): all again within one 
or other of the paramagnetic iron belts. Some nickel 
found in New Caledonia would occupy a position very 
nearly half way between the iron belt of Central Asia 
and the iron of California. 
Without going into further details at present regard- 
ing the paramagnetic metals and their ores, let us ex- 
amine some of the 
n. DIAMAGNETIC METALS AND THEIR ORES. 
1. Gold. This metal cooling among the first on 
the globe is found in old formations ; but appears to 
be also injected into, or deposited in, the fractures 
and fissures of rocks having a more recent age. The 
earlier east and west ranges or belts, in which it 
2 A degree of longitude in latitude 40° is about 53 statute miles : conse- 
quently the width of the belt is nearly 750 miles. 
3 The average latitude of European iron being about 54° to 55 0 N., we 
may call a degree equal to 40 statute miles, thus giving the above result. 
occurs more or less, often correspond, as already 
stated, with parallels of latitude ; thus we find gold on 
a belt of the parallels 55 0 to 6o° N. lat., comprising 
the gold of Alaska, Scotland, Sweden and the Urals ; 
again in a belt ranging from lat. 45° to 50° N., em- 
bracing the gold of British Columbia, Washington 
Territory and Oregon, of Lake Superior, Canada and 
Nova Scotia, in North America. We find on the 
same parallels or belt, in the eastern continent, the 
gold of the Alps, Tyrol, Hungary and the Altai 
Mountains. Another zone or belt, in about lat. 35° 
to 38° N., runs from California and Arizona, through 
Georgia and North Carolina, and is prolonged through 
Spain, Thibet, China and Japan. A more southerly 
belt marks the gold of Central America and New 
Granada (United States of Colombia, S. A.), also of 
Western and Eastern Africa (about 5° N. of the 
Equator), as well as of Ceylon, Java and Borneo. 
The most southerly belt, in about lat. 22° to 32 0 S., 
embraces the South American gold localities, the gold 
washings of South Africa, the rich mines of Australia, 
and almost includes the gold of New Zealand. 
In some cases, without making the belt so broad, 
gold localities can be traced on one and the same 
curve, using either the northern focus of each conti- 
nent for a centre, or occasionally the more southern 
continental focus. For instance, using the Boothia 
Felix focus as a centre, an arc unites the gold of Ore- 
gon with that of Canada, while from the Lake Superior 
focus a curve sweeps from the gold of the Sierra Ne- 
vada and the Sacramento Valley in California to that 
of Georgia and North Carolina. 
2. Silver. The most noted localities for this useful 
metal can be readily traced in North America, Europe 
and Asia, on belts running east and west, often at 
vertical intervals of about 4 0 to 5° apart, or say every 
300 statute miles. Thus we have a belt from the 
silver of Norway to that in the Urals ; then another, 
from Montana, Idaho, Wyoming and Lake Superior 
regions, continued through England, France and Sax- 
ony to the Altai Mountains ; a third silver girdle runs 
from California and Arizona, through Utah and Colo- 
rado, thence to Spain. A fourth shows that of Mex- 
ico on the same parallel with the silver of China. 
Then come the rich mines of South America, in three 
successive belts (that of Venezuela, of Brazil and of 
Bolivia), with nothing to correspond in the eastern 
continent. 
3. Copper can equally readily be traced along belts 
on diamagnetic parallels ; such as one in Scandinavia 
connecting with the Urals. A second, on the parallel 
of the rich Lake Superior region takes in the copper 
of Cornwall, of France, Thuringia, Hungary, Siberia, 
China and Japan ; a third can be found embracing 
the mines of Arizona, New Mexico, Tennessee and 
North Carolina, also of the Island of Cyprus, of 
Turkestan and Persia; a fourth gives us the copper 
of Cuba, Africa, Arabia and Hindostan, as shown in 
map No. VIII, of Cornell’s Phy. Geogr., by Stein- 
wehr. Of the two copper belts in S. America, the 
more Southerly is on the same parallel with the cop- 
per of Australia. 
4. Tin (although sparingly distributed, except in 
two or three localities) follows the same rule : First 
belt, Massachusetts, New Hampshire, Cornwall (Eng- 
land), Saxony, Austria, and Russia. Second belt, 
