February 16, 1894. 
and mouth under a notched rim. One detached face has 
much the character of some of the heads at Hoclulago, but 
the Onondagas seem to have made some terra cotta articles 
merely as ornaments. 
Two other later sites, not far off, supply some more 
articles of this kind, but it is needless to describe all of 
these. Quite a number have been passed over now. .On 
the earliest of these Onondago sites are occasionally found 
some large and curious clay pipes, with from four to five 
grotesque faces encircling the top of the bowl, while 
others intertwine all down the curving sides even to the 
mouthpiece. Ihaveseenthem nowhere else. 
Of this pottery one fragment with a face at the angle 
was recently found on a fishing site near the head of 
Onondaga Lake. It is of interest as showing that the 
Onondagas even then visited the lake, though their homes 
were far away. It is interesting, too, to find that the 
Mohawks and Onondagas, the real founders of the Iro- 
quois League, both had this unique pottery for a short 
time three centuries ago, and that it has not yet been 
found in the homes of the other Iroquois. 
HOW ALUMINIUM IS OBTAINED FROM ITS 
ORES. 
ALUMINIUM is now so rapidly growing in demand with 
the cheapening of the metal that it attracts more or less 
popular attention. In the form of clay the metal is all 
around us, but this ore is too poor in the metal and too 
dificult of working to make it a profitable source of 
supply. Corundum is the oxide and theoretically nearest 
the metal from a metallurgical point of view. Indeed, 
the metal has been extracted from this mineral on a small 
commercial scale, but the supply is too limited. 
The metallurgy of the aluminium is theoretically the 
same as iron, that is, the compound used for extracting 
the metal is in each case an oxide. The oxygen in both 
cases is» removed by carbon. ‘The facility of carrying 
into practice the extraction of the metal is entirely 
different. In an ordinary blast furnace the carbon of the 
coal or coke easily extracts the oxygen from the iron 
ore, so that a pound or two of coal produces a pound of 
metallic iron. The oxide of aluminium defies such easy 
processes, and requires a temperature vastly greater 
than the fiery iron furnace. ‘This is obtained by electric 
currents, and a process of electro-metallurgy is adopted. 
A trough is lined-with gas carbon. In this, cryolite to the 
extent of 500 pounds is placed. Into this press, 
enormous electrodes are inserted, and the heat melts the 
_cryolite, which is not decomposed by the electricity. 
With this fused mineral, about a third of its weight of 
oxide of aluminium is mixed, and it is soon dissolved. 
In this condition the aluminium compound is decomposed, 
the oxygen being removed at the expense of the carbon 
electrodes, and the molten particles sink in the cryolite. 
As the cryolite (fluoride of aluminium and sodium) is not 
consumed, the operation is continuous. However, the 
affinity between the metal and oxygen 1s so great that not 
merely the carbon of the electrodes is consumed, but 
about 75 pounds of coal are needed to develop horse- 
power to produce electricity enough to decompose the 
oxide. 
From the method pursued, we see that the ore most 
available is that nearest approaching an oxide and rich in 
the metal. Of the natural compounds occurring’ in large 
quantities, beauxite is the most important. This is 
essentially a hydrated oxide of aluminium, but with 
usually an admixture of oxide of iron and frausilica. A 
high grade ore contains 60 per cent of alumina, only one 
SCIENCE. 89 
or two per cent of each of the other constituents, and the 
balance is water. In this country the beauxite occurs in 
Georgia, Alabama and Arkansas. It is from the recent 
volume on the Paleozoic Belt of Georgia, by Dr. J. W. 
Spencer, that we derive the materials for this notice. 
This report is the most exhaustive treatise upon beauxite 
which has appeared in this country. The mineral occurs 
as masses of small concretions in great products in 
the Knox dolornite (the lowest formation of the 
Lower Silurian system). Where it is formed, the 
calcerous matter has been leached out of the impure 
limestone, leaving a great mass of a peculiar siliceous 
clay or loam, which is sometimes 200 feet thick. This 
represents that as much as 2000 feet of limestone have 
been removed from the region, which has been exposed to 
atmospheric degredation for long geological ages. As 
the alumina has resisted solution, a process of concentra- 
tion has gone on so that the accumulations make them- 
selves conspicuous. The ore always occurs in proximity 
to brown iron and manganese ores. ‘The author explains 
their occurrences as having been brought down in solution 
by streams and deposited in lagoons, in which the lime- 
stones were also forming. The author gives us here an 
interesting chapter on chemical geology, without saying 
so in his treatment of the origin of the beauxite. Under 
the conditions of occurrence ferric oxide often replaces a 
portion of the alumina, sometimes to the extent of twelve 
or fifteen per cent. This, however, is no injury, for in 
preparing alumina for furnace uses a valuable bye-product 
is obtained. Silica may sometimes reach 20 ©r 30 per 
cent. In this case, the mineral must be considered more 
or less a mixture of beauxite and clay. Amongst the 
beauxite, iron and manganese deposits, great pockets or 
‘“‘horses” of clay, or often kaolin, are frequently seen. 
When the silica is present in such quantities the mineral 
becomes too poor to be of use. For making alumina the 
beauxite is fused with soda, from which mass the pure 
alumina is extracted. With the visible supply of beauxite 
and greater economy in the power consumed, we may 
hope before very long to see the metal at twenty-five or 
thirty cents a pound, when its uses in the arts will be 
enormously increased. 
—When we examine the total number of books that 
have for their subject an Oriental country we are sur- 
prised to find how large a proportion of them have been 
written by travelers who were there for a comparatively 
short period, who did not understand the language of the 
people they describe, and whose knowledge must, conse- 
quently, have been acquired mainly at second-hand. It is 
a pleasure, therefore, to find in Miss Adele M. Fielde’s 
forthcoming volume—‘‘ A Corner of Cathay "—a graphic 
record of original research concerning the life of the 
Chinese, by one who lived among them for twenty years, 
and whose familiarity with their language enabled her to 
enter into their modes of thought, and to ascertain from 
themselves the reasons for their peculiar and amazing 
customs. Asan inmate of native households she possessed 
peculiar facilities for a study of their life, domestic, social, 
and intellectual, from the question of the legal status of 
the women to the curious games played by the children. 
In her illustrations she was aided by a native artist of 
wide local fame, and his pictures, as winsomely guiltless 
of perspective as were those of the early Italian artists 
and as charming in tint as Pekinese enamels, are skilfully 
reproduced in colors and present a new feature in American 
illustration. ‘The name of the book is taken from the 
populous and picturesque region about Swatow, in the 
China. It will be published by 
southeastern corner of 
Macmillan & Co. 
