616 
geneous sphere made up of layers of uniform 
density, but increasing in density towards the 
center. 
The radiation as at present determined is as- 
sumed to apply to all time past and present, 
and the density is assumed to vary from center 
to circumference, in accordance with Lane’s 
deductions in 1870, the value of K, the ratio of 
the two specific heats being 1.4. 
Lane found the density at the center to be 23 
times that of water, and by a different process, 
Kelvin has found it to be 32 times that of water. 
Assuming a surface temperature of 8,000 de- 
grees, as found experimentally by Wilson and 
Gray, the temperature at the center comes out 
256,000 degrees C. 
The potential of the heterogeneous sun thus 
assumed is then found by mechanical integra- 
tion, by dividing the radius into 40 parts, the 
density of each shell being constant. 
The energy developed by the falling together 
of the parts of this heterogeneous sun is greater 
than for the homogeneous sun of Helmholtz in 
the ratio of 176 to 100. As in the past history 
of the Helmholtz sun, the radiation would have 
dissipated this heat at the present rate of radia- 
tion in 18 million years, it follows that if the 
Helmholtz sun should pass into the hetero- 
geneous sun, discussed by See, by inward 
gravitation of particles, the past history is in- 
creased by about 14 million years. This aug- 
mentation of its past is at the expense of its 
future duration. 
The author gives reasons for thinking that 
condensation cannot go on unchecked by molec- 
ular forces after the radius has shortened to much 
over one-half its present length, and assigns 36 
million years as a fair value for the total life of 
the sun from the time its radius was that of 
Neptune’s orbit to the time when its radiation 
will become insignificant. Of this total period 
32 million years, or 8/9 of the whole, have al- 
ready elapsed, leaving four million years for a 
fair estimate of its future duration, with the 
conditions assumed. 
There is reason to believe that under the 
immense temperatures existing in the sun, the 
gaseous mass may be so dissociated that all 
gases behave like monatomic gases. This would 
increase the ratio of specific heat at constant 
SCIENCE. 
[N. S. Vou. X. No. 252. 
pressure to that of constant volume from 1.4 to 
1.66. This changes the law of density and 
temperature along the radius. The density at 
the center becomes much less and the poten- 
tial of the whole mass upon itself is corre- 
spondingly less exhausted. It increases the 
probable future life of the sun from four to 
13 millions of years, and diminishes its past 
history from 32 to 23 million years. The author 
concludes that life as it now exists on the earth 
cannot be maintained longer than three million 
years, and after five or ten million years, the 
planet will have become a rigid and lifeless mass. 
Dr. H. von Schrenk presented some notes 
on Arceuthobium pusillum which was found in 
Maine, during the past summer, growing on 
the white spruce along the sea-coast. The 
trees which are attacked form large witches’ 
brooms, the branches of which are much longer 
than the normal branches. The manner in 
which the seeds are distributed was briefly de- 
scribed, and seeds were exhibited adhering to 
branches of the white spruce. 
WILLIAM TRELEASE, 
Recording Secretary. 
WASHINGTON CHEMICAL SOCIETY. 
THE regular meeting was held May 11, 1899. 
The first paper of the evening was read by 
Professor F, W. Clarke and was entitled: ‘ Hx- 
periments on the Constitution of Certain Sili- 
cates,’ by F. W. Clarke and George Steiger. 
The paper cited some results obtained by 
Clarke and Schneider in 1889-92. The present 
work led to the following conclusions : 
1. That pectolite is a metasilicate. 
2. That the formula for pyrophyllite is pos- 
sibly that of a basic di-metasilicate. 
8. That calamine is probably a basic meta- 
silicate which is in accord with the accepted 
formula. 
With analcite a very interesting ammonia 
compound was formed, by heating with am- 
monium chloride. Other experiments agreed 
closely with those made by Friedel and it was 
concluded that this mineral is a mixture of 
ortho- and tri-silicates. 
The last paper of the evening was ready by 
Dr. H. N. Stokes and was entitled: ‘ Indexing 
Organic Compounds.’ 
