326 
POPULAR SCIENCE REYIEW. 
diffuses itself throughout the space. Some of the experiments with this 
substance were of great interest. When nitrogen, air, nitrous oxide, carbonic 
acid, and carbonic oxide were used, the luminosity was in each case pro- 
duced; but when hydrogen was employed, not the slightest appreciable 
effect was obtained. M. Sarasin gives the following hypothetical explana- 
tion of these phenomena : — The nascent oxygen or ozone is diffused 
throughout the space. In this state it has a very strong tendency to com- 
bine with the elements in its presence, and in fact up to the time that the 
current ceases it recombines with them. This recombination of nascent 
oxygen or ozone, being effected with great energy, must be accompanied 
with a considerable degree of heat, and this in its turn produces the lumi- 
nosity to which the term phosphorescence is given. — Comptes-RenduSj 
April 12. 
Aneio Battery for Telegraphic purposes, but which may perhaps be gene- 
rally useful, has been invented by M. Guyot, and apparently is not unlike the 
ordinaiy Menotti sand battery. It consists of a porous earthen vessel filled 
with finely-powdered iron ore, in which is plunged a cylinder of gas-retort 
charcoal and an ordinary vessel filled with concentrated solution of common 
salt, in which is placed a slip of zinc. The only care required to keep such 
a battery in order is to keep the latter vessel always full of concentrated 
solution. Further the solution may be replaced by sand impregnated with it, 
or by salt in crystals, the humidity of the atmosphere being always suffi- 
cient to serve as a solvent. 
The Physics of the Gulf Stream. — M. Janies Croll, who has published some 
papers on this subject, speculates thus as to the stream as a heat-caiTying 
medium. The total quantity of water, he says, conveyed by this stream is 
probably equal to that of a stream 50 miles broad and 1,000 feet deep, fiowing 
at the rate of four miles an hour. And the mean temperature of the entire mass 
of moving waters is not under 05° at the moment of leaving the Gulf. I 
think we are warranted to conclude that the Gulf Stream, before it returns 
from its northern journey, is on an average cooled down to at least 40°, con- 
sequently it loses 25° of heat. Each cubic foot of water, therefore, in this 
case carries from the tropics for distribution upwards of 1,500 units of heats, 
or 1,158,000 foot-pounds. According to the above estimate of the size and 
velocity of the stream, 5,575,080,000,000 cubic feet of water are conveyed 
from the Gulf per hour, or 133,810,320,000,000 cubic feet daily. Conse- 
quently, the total quantity of heat tiansferred from the equatorial regions 
per day by the stream amounts to 154,959,300,000,000,000,000 foot-pounds. 
From observations made by Sir John Ilerschel and by M. Pouillet on the 
direct heat of the sun, it is found that were no heat absorbed by the atmo- 
sphere, about 83 foot-pounds per second would fall upon a square foot of 
surface placed at right angles to the sun’s rays. Mr. Meech estimates that 
tlie quantity of heat cut off by the atmosphere is equal to about 22 per 
cent, of the total amount received from the sun. M. Pouillet estimates the 
loss at 24 per cent. Taking the former estimate, G4’74 foot-pounds per 
second will therefore be the quantity of heat falling on a square foot of the 
earth’s surface when the sun is in the zenith. And were the sun to re- 
main stationarj' in the zenith for twelve hours, 2,790,708 foot-pounds would 
fall upon the surface. 
