AuGust 18, 1899. ] 
rotates rapidly, the direction of rotation depend- 
ing upon that of the field, but not of the dis- 
charge. This, Thomson explains by electrified 
molecules passing inward from the walls of 
the tube and set in rotation by the growing 
field. 
In the London Electrician of July 7th P. A. 
C. Swinton describes experiments upon the in- 
eandescence of Thoria and Ceria as heated by 
bombardment in a vacuum tube. He states that 
in the Bunsen flame Thorium oxid and Cerium 
oxid give about the same degree of incandes- 
cence, and that the addition of one per cent. 
of the latter to the Thorium oxid, as in the 
Wellsbach mantle, increases the incandescence 
about eleven times. In the vacuum tube, how- 
ever, the ceria was but a dull red, when the 
thoria was at full incandescence, and the same 
was true of a mixture of half and half; further 
the addition of the one per cent. of ceria to the 
thoria increased the incandescence only about 
five per cent. This seems to favor the theory 
that chemical action takes place in the action 
of the Wellsbach mantle. The energy used was 
about one watt per candle. 
135 (Ch Ob 
NOTES ON INORGANIC CHEMISTRY. 
ATTENTION was recently called to the re- 
searches of Armand Gautier on the occurrence 
of iodin in ocean water. A continuation of his 
work takes up the iodin in the water of the 
Mediterranean Sea. The surface water, like 
that of the Atlantic Ocean, contains no iodids 
or iodates, but the iodin is present either in 
microscopic organisms or in complex organic 
compounds containing also nitrogen and phos- 
phorus and capable of dialysis. The total 
amount of iodin present is the same for all 
depths, but variesinits form. Thus at the bot- 
tom of the sea iodids and iodates are present to 
the extent of 0.305 milligrams per liter, while 
they are zero at the surface. Of iodin in living 
organisms there is a maximum at the surface 
and none at the bottom. The soluble organic 
iodin is more constant, though varying to some 
extent with a maximum at 880 meters depth. 
The total iodin present is 2.25 mg. per liter, 
which is but little less than the 2.40 mg. found 
in the water of the Atlantic Ocean. 
SCIENCE. 
221 
THE same number of the Comptes Rendus con- 
tains an account of the preliminary work by F. 
Garrigon on the occurrence of rare metals in 
water. He finds evidence of the presence of a 
number of unexpected metals, particularly those 
of the copper and tin groups. As titanium has 
been found not only as a constant constituent of 
almost all soils by Dunnington ; but of many, if 
notall, plants by Wait ; and of animals including 
man—unpublished work of Wait (Univ. of 
Tenn.), Toole (Wash. & Lee.), and Baskerville 
(Univ. of N. C.)—it is not unnatural that traces 
of it should be found in mineral waters. 
ONE of the greatest drawbacks to work on 
the element fluorin has been that the apparatus 
used must be of platinum or fluor spar. Mois- 
san has, however, now shown that copper ves- 
sels can be used even for the electrolysis of 
hydrofluoric acid, being less attacked than 
other metals. The cause of this appears to be 
that there is formed on the surface of the cop- 
per a very thin layer of the fluorid of copper, 
which is wholly insoluble in hydrofluoric acid, 
and, of course, unattacked by free fluorin. 
THREE papers have recently been read before 
the Chemical Society of London by Harold B. 
Dixon, which are of considerable interest. The 
first is on the combustion of carbon bisulfid. He 
finds it burns in the air with phosphorescence, 
which, however, begins to appear at 230°, 
while real ignition does not begin till 232° is 
reached. Carbon bisulfid is not decomposed 
by leading through a tube at 400°. It can be 
detonated by a heavy blow, but the explosion 
is not propagated through the vapor. The 
rapidity of explosion is greatest when exactly 
sufficient oxygen for combustion is present. 
A SECOND paper is on the combustion of coal. 
It is ordinarily accepted that carbon burns di- 
rectly to carbon dioxid and that this is sub- 
sequently reduced by the excess of carbon to 
earbon monoxid. Professor Dixon finds that 
when a mixture of air and carbon monoxid is 
passed slowly over coal at 500° the amount of 
carbon monoxid is unchanged, but the oxygen 
disappears completely by union with carbon to 
form carbon dioxid. On the other hand, if a 
mixture of 20% carbon monoxid and 80% oxy- 
gen is used, and the current is very slow, the 
