Vol. XXV. No. 6.] 
POPULAE SCIENCE NEWS. 
87 
Sf^e p^opcjlap (Bcience ^e\A7§. 
BOSTON^, JUNE 1, 1891. 
AUSTIN P. NICHOLS, S.B Editor 
WILLIAM J. KOLFE, LITT. D. . . ASSOCIATE EDITOK 
An interesting investigation lias recently been 
conducted by MM. Bekthelot and Andre upon 
the cause of the peculiar and agreeable odor given 
• off by the earth when moistened by a shower of 
rain. They find that the essential principle of 
this odor is a volatile hydrocarbon of the aromatic 
family which is carried away with the vapor of 
water. The proportion present in tlie soil is 
exceedingly small, probably not exceeding a few 
millionths. Referring to this discovery, Dr. Puip- 
sox, of London, writes to the Chemical News in 
regard to some similar investigations made by 
himself in 186.5, in which he succeeded in separat- 
ing the odoriferous substance from the soil by 
means of a solution of bromine, and found it to be 
of a yellowish color, soluble in alcohol, and simi- 
lar to, if not identical with, a body known as 
bromo-cedren, derived from essence of cedar. 
Phipson thinks that in dry weather many soils 
will absorb the fragrance emitted by flowers, giv- 
ing it up again when moistened. 
A KEJiAiiKABLE paper upon the atomic weight 
of oxygen has been published in the American 
Chemical Journal, by E. H. Keiseh. All previous 
determinations of this important chemical stan- 
dard have shown a value lowfir than 16, but not 
lower than 15.90. Mr. Keiser has made a deter- 
mination of this weight by a method which per- 
mits of a separate weighing of the hydrogen, 
oxygen, and the water formed by their combina- 
tion, and, after taking every possible precaution 
against error, finds that his results slxow that 
oxygen has an atomic weight of about 16, thus 
agreeing with Proufs hypothesis. If these re- 
sults are confirmed they will have an important 
influence upon the present theories of the atomic 
constitution of matter, and, it may be said, in the 
direction of a much greater simplicity, for if it 
should be found that the ratio of weight between 
hydrogen and oxygen is a whole number, it is 
less improbable that a similar simple relation exists 
between hydrogen and the other elements. 
At the recent meeting of the National Academy 
of Science at Washington, much interest was 
excited by a paper read by Professor S. P. I.ang- 
LEY, on "Flying Machines," in which he took the 
ground that it was by no means impossible for 
mankind to discover a method of moving througli 
the air in any desired direction, and that the 
amount of power required for artificial flight was 
perfectly attainable by such steam engines as 
we now possess. He also claimed to have dis- 
covered by his experiments that a given amount 
of power will transmit a much heavier weight at 
a rapid speed than at a slow one— a conclusion 
that is apparently in contradiction to the funda- 
mental principle of the conservation of energy. 
Professor Langley's eminent scientific reputation 
requires that any statements made by him re- 
ceive the most careful and respectful considera- 
tion, but we cannot help thinking that the day of 
a practicable flying machine is a very distant one, 
and that there are a great many difflculties enter- 
ing into the solution of the problem which would 
not appear in a theoretical discussion, but whicli 
mechanical enghieers would find insurmountable. 
The artificial production of naturally occurring 
minerals forms the subject of an interesting 
paper published by M. Kroustchoff in the 
Comptes Eendus. His latest work has been the 
production of crystals of artificial hornblende 
which were identical in every respect with the 
natural ones. The process consisted in placing 
the various oxides, mixed with an aqueous solu- 
tions of silica, in small glass flasks from which 
the air was exhausted, and digesting the mixture 
for three months at a temperature of about 1,000° 
F. In addition to the hornblende, crystals of the 
augite, zeolite, and feldspar families were formed 
in the flask, as well as small quartz crystals with 
cavities containing liquids and gases similar to 
those found in nature. 
We hope for the sake of the reputation of the 
New York City Board of Health, that a recent 
alleged interview with its President, as reported in 
the daily papers, was an imaginary one. A man 
was recently arrested in that city charged with a 
most atrocious murder of a woman, and particles 
of dried blood were removed from his hands and 
clothing and submitted to a microscopical exami- 
nation. According to the newspaper repoi-t, the 
gentleman above alluded to was made to say that 
the microscope showed that the blood on the 
hands of the man arrested for the crime was not 
only that of a female, but that it was identical in 
its special characteristics with that of the particu- 
lar woman who was murdered. It is hardly 
necessary to say that there is not only no dift'er- 
ence whatever between the blood of dtfterent indi- 
viduals or sexes, but that it is an extremely difli- 
cult matter to distinguish between human blood 
and that of many other mammalian animals, 
especially after it has dried. This reported inter- 
view was a fine example of newspaper science, 
but no physician with even an elementary knowl- 
edge of the subject would have made such ridicu- 
lous statements, and it is most probable that the 
whole story originated in the brain of some enter- 
prising reporter anxious to contribute his share 
to the sensation of the liour. 
Keauers of the Science News will be pleased 
to learn that, at the annual commencement of the 
.Jefferson Jledical College, Philadelphia, on the 
1.5th of April, the honorary degree of Doctor of 
I>aws was conferred on Dr. Daniel G. Brinton of 
Philadelphia, in recognition of his researches in 
anthropology and ethnology. 
. +♦« 
[Special Correspondence of Populae Science News.] 
PARIS LE'rrER. 
It is a curious but well-ascertained fact that no 
living being can live over a certain time in a given 
medium, and that the environment must be re- 
newed, or else death is inevitable. Everybody 
knows that a rabbit, or a bird, or any animal, dies 
quickly when breathing in a confined space. It 
dies because there is not oxygen enough left in 
the air, or because carbonic acid is becoming too 
abundant. Some physiologists have believed, 
however, that there may be something more, and 
that the animal poisons its own environment in 
more than one manner. Brown-Sequard, in the 
last instance, has performed experiments from 
which he has drawn the conclusion that the air 
expelled from the lungs, in addition to the delete- 
rious effect it produces by being poorer in oxygen 
and richer in carbonic acid, is a poison through 
some substance which is expelled, or which per- 
spirates through the lungs. The way in which 
the experiment was conducted consisted in com- 
pelling the air expired by a man or animal to pass 
through a small body of water so as to saturate 
the water with the supposed poison; and the 
water was said to be poisonous when inoculated 
under the skin. Many observers have repeated 
Brown-Sequard's experiments, and, in fact, have 
given them no support. In the cases where 
Brown-Sequard has really obtained toxic effects, 
it seems likely that some of the saliva has passed 
into the water, and this is enough to induce septi- 
caemia in most cases. If the experiment is con- 
ducted in such a manner as to prevent all matters 
other than gaseous to pass into the water, the lat- 
ter rem.ains as perfectly innocent and innocuous 
as usual. Brown-Sequard's experiments have 
been quite recently repeated by two Italian ob- 
servers, and the result is that not the slightest 
toxicity can be detected. We may rather con- 
gratulate ourselves on the result. It is already 
quite enough that animals are poisonous to others 
and to themselves through their mere respiration, 
and that, in addition to this, danger attends 
breathing in a space where some 'diseases — such 
as tuberculosis — are present. 
Concerning this toxic influence of living beings, 
on themselves, which may be shown in a thousand 
ways, and also often explained in a Siitisfaetory 
manner, I would recall the explanation given in 
one particular case by Prof. Carl Semper (c/. Ani- 
mal Life) . The case is that of the common pond 
snail (Lymnoea stagnalis). When this animal is 
kept in aquaria of small size, a very noticeable 
dwarfing is the result ; for instance, of two snails 
from the same bunch of eggs, the one reared in 
five liters of water will attain in three months, 
say, the length of twenty-five millimeters, while 
the one reared in a quarter of a liter of water will 
hardly attain eight or ten millimeters. Of course 
many agents may be at work in this sort of ex- 
periments, and there is some difficulty in deter- 
mining their influence, but really the explanation 
given by Semper seems a very far-fetched one. 
He thinks that the facts are to be explained by 
the supposition that there is in water generally 
some unknown substance, which, while not used 
as food, is conducive to the growth and nutrition 
of the animal. In a small body of water there is 
but little of this substance, and the consequence 
is that growth is arrested or retarded. But this 
explanation does not hold against this fact, that 
in a small body of water on a large surface the 
animal grows very well, while in the same body 
of water with a small surface it remains small. 
Is it then a matter of aeration? No; facts dis- 
prove the idea. There is some other element, and 
everything goes to show that the reason which 
prevents pond snails from growing normally in 
small bodies of water is merely the fact that in 
such bodies, when the surface is small, the animal 
cannot take exercise enough ; and when, although 
the volume of the water is small, the surface is 
large— the water being very shallow — the animal 
grows well. Why does it not take in a small- 
surfaced volume of water the necessary exercise? 
Because it likes keeping near the surface, where it 
comes to breathe, and does not willingly go deep. 
In a small-surfaced volume of water it has, in 
fact, little space, while in a large surface of iden- 
tical volume it has much space, the shallowness 
of the water being of no consequence. This is a 
new proof of the necessity for exercise; it was 
not necessary, however, as all are convinced of 
the usefulness thereof. 
Speaking of poisons, I would signal to our read- 
ers a recent p.aper by A. de Mortillet in the Beoue 
Mensuelle de VEcole d^Anthropologie — a new pef iodl- 
cal recently started by the professors of tlie Paris 
