1877*] The Chemistry of the Future. 293 
silicon, glucinum, cerium, lanthanum, didymium, ruthenium, 
iridium, palladium, and platinum. The remaining terres- 
trial bodies may possibly still be discovered in the sun, as 
there are many lines not yet identified. On the other hand, 
it is quite possible that some of these lines may indicate the 
presence in the sun of elements other than our own, and 
possibly of a simpler nature. 
The spedtra of the stars again differ from those of the 
sun. Meteorites have not, to our knowledge, been subjected 
to as careful and thorough spectroscopic examination as 
they deserve ; but on ordinary chemical analysis they are 
found to contain some of the elements present in the earth, 
but wanting in the sun, viz., silicon, potassium, tin, and 
probably antimony, arsenic, and lead. 
Thus we see that nineteen well-charaCterised terrestrial 
elements are absent in the sun. To explain this facft three 
hypotheses may be proposed : — We may assume that each 
sun or planet is a body independent in its origin and mate- 
rials, and not therefore necessarily containing the same 
chemical elements as its neighbours. This view is, of 
course, irreconcilable with the nebular hypothesis, and 
though it might have met with general acceptance in the 
beginning of the century, we think it will fail to command 
the assent of the most judicious physicists of the day. 
Or, secondly, we may conceive that the missing elements, 
from some of their attributes, are more likely to escape ob- 
servation than are others. It is quite possible that simple 
bodies present in the sun in exceedingly small proportions 
-—bodies of very high specific gravity or of sparing vola- 
tility — might not be recognised in the speCtrum ; but on 
going carefully over the list of the missing elements we can 
scarcely pronounce such considerations admissible. Among 
these elements we find one, silicon, which on our earth ranks 
among the most plentiful bodies. We perceive, indeed, cer- 
tain bodies of a decidedly fixed character, — such as gold, 
platinum, and iridium, — but along with these occur such 
signally volatile substances as potassium, mercury, arsenic, 
and antimony. The heaviest bodies are included, such as 
gold and platinum, but also lithium and potassium, which 
are remarkably light. Perhaps we may say that the missing 
elements have, on the average, higher atomic weights than 
those bodies found present in the sun.* Yet the former list 
includes glucinum and lithium, which rank, in this respeCt, 
* This circumstance, we think, favours the hypothesis of the compound 
nature of our present elements. 
