288 BOTANICAL GAZETTE [aRin 
extension and impenetrability — the qualities of touch— disappear along with 
color and odor, gone perhaps to look for the hole in the cookie after the 
cookie has been eaten. 
From these premises Dr. Wagner considers himself entitled to conclude 
that the atom and the ether are pure mythological entities. But here he cer 
tainly moves too fast. That the atom does not exist in the sense in which 
materialism supposes it does may well be conceded, but, though essentially 
intangible and invisible, the question whether it may not exist in the same 
sense in which the flower that is “born to blush unseen” may be said to bea 
reality, is another problem — one to be decided by a study of evidence which 
lies entirely outside of the province of the metaphysician as such to discuss. 
As well might he have dogmatized about the formation of crystals from soli: 
tions before Leuwenhoek turned his microscope upon them, or about = 
cause of tuberculosis while Koch was still experimenting with staining fluids. 
In our use of the word “cause” we have laid ourselves open to another 
criticism which our author directs against the atomic theory. The only 
efficient causes, he tells us, are the forces that lie behind phenomena, and, 
therefore, to talk of the atom or the ether as active agents in the production 
of change is an absurdity. In one sense this is true enough, but _ 3 = 
cism upon the use of these terms by a scientist who knows his bonne’ fe 
irrelevant. The invisible water in the form of steam, in the cylinder of 
engine, is j ing work as is the visible wattt 
gine, is just as truly an agent capable of doing erie 
that turns a mill wheel. Perhaps in all strictness we ought to speak ae 
the unknown forces that lie behind the steam, as the true agent, ¥ pene 
revise in a corresponding manner our everyday language about a - as it bas 
It will be seen that Dr. Wagner's book, clearly and convincingly per 
stated some fundamental truths, is a horrible example of the pas oe 
scientific and the metaphysical problems raised by the world of we ora 
he is not the first. His immediate predecessor in this ss ve a a weap 4 
Professor Ostwald, who seems to think he has found in ce a4 
with which to destroy a theory which he himself has probably Mistaking a 
other grounds. And then there are the “scientific materialists. 
the atom for a metaphysical entity they suppose themselves 
the clue to the nature of ultimate reality. Revilin 
themselves have swallowed whole one of the shallowest 
metaphysical systems —a spectacle which would certainly vi 
amusing in the history of thought, if it were not at the same 
most mournful.—F RANK CHAPMAN SHARP. 
Lessons with plants. “ 8 
| wee 
ANOTHER BOOK comes to us from the pen of pee * which it ® 
which is likely to be highly acceptable to the constitu 
