APRIL 11, 1884.| 
above the intestine, against the spinal column. The 
presence of this air-bladder allows a fish to rise and 
sink with great ease. In the case of a fish taken at 
a great depth, and brought to the surface, the gases 
enclosed in this bladder expand to a very consider- 
able extent. As a result, the bladder presses upon 
the abdominal wall, and, as this expands, it gradually 
loses by abrasion the scales which cover it. When the 
expansive limit of the bladder is reached, its lower end 
pushes against the stomach, on the head of which 
it rests, enters the mouth, and leaps outside. The 
pressure which is thus brought to bear on the upper 
wall of the mouth-cavity is so great that it yields, 
and the eyes are forced from the sockets. We have 
endeavored, in fig. 12, from a specimen in the exhi- 
bition of the Talisman, to show in what state fishes 
caught at a great depth are brought to the sur- 
face. The same enormous pressure, brought to bear 
upon the collecting implements, may be understood 
Fie. 13.— Effect of deep-sea pressure on cork. 
from the injury to one of their parts. In order to 
keep the mouth of the trawl-net open, there is ar- 
ranged within a set of large cork disks strung on a 
string. These disks, when new, have a rather large 
diameter, but after a few days’ use they shrink to 
about half their original size. Under the pressure 
exercised, the tissue of which they are made settles 
considerably, and at the same time becomes as hard 
as wood. Fig. 13 shows different sides of two of 
the disks, — one before use, the other after, — drawn 
upon the same scale. 
THE USE OF NAPHTHALINE AS AN 
INSECTICIDE. 
NAPHTHALINE, in one form or another, has for 
some time been used by entomologists as a means of 
preventing injury to their collections from Acari, 
Psoci, Dermestes, Anthreni, and other museum pests. 
My own experience is, that it destroys the Acari and 
Psoci, but not the other pests, though it tends to re- 
pelthem. Recent investigations would seem to in- 
dicate that it may be used to advantage in the field 
as an underground insecticide. It appears that as 
early as 1842 a French physician, Rossignon, pointed 
out the possible use of naphthaline, not only as a 
remedial agency in medical practice, but also as a sub- 
stitute for camphor, for the destruction of museum 
pests. But up to the appearance of the grape Phy]l- 
loxera in France, no serious experiments were made 
with it in the field. Among the substances tried 
1 Das naphtalin in der heilkunde und in der landwirth- 
schaft. Von Dr. Med. Ernst FiscueR. Strassburg, T7riibner, 
1833. 
SCIENCE. 455 
against this pest, naphthaline played its part. The 
efficient ingredient in the ‘poudre insectivore’ of 
Peyrat, was, according to Maurice Girard, naphtha- 
line; but the experiments with it did not yield en- 
couraging results. 
Baudet recommended it to the French academy in 
1872; while in 1874 E. Fallieres proposed gypsum 
saturated with naphthaline, the mixture to be dis- 
tributed over the soil. It was also among the numer- 
ous substances experimented with by Messrs. Maxime 
Cornu and P. Mouillefert, the results of which were 
published in the well-known memoir presented by 
these gentlemen to the French academy in 1877. 
Naphthaline, up to this time, proved to be of little 
value in killing the insect, and of no value as a repel- 
lant. Nevertheless, Dr. Ernst Fischer of the Strass- 
burg university, encouraged and induced by the most 
favorable results obtained with naphthaline as an anti- 
septic and as a destroyer of micro-organisms (moulds, 
Schizomycetes, Bacteria, etc.), has, since 1881, again 
experimented with it as a direct remedy for the Phyl- 
loxera; and he has given us the results of his experi- 
ence in an interesting brochure lately received. The 
first part of Dr. Fischer’s work treats of, and strongly 
recommends, the use of naphthaline for surgical pur- 
poses as an antiseptic superior, in most respects, to 
all other antiseptics now in use. His conclusions are 
based on extensive experiments showing the effect of 
the material on the lower organisms, and prove, that, 
properly used, it not only arrests the growth of these 
micro-organisms, but eventually destroys them. This 
part of the work will be of especial interest to those 
who are experimenting with a view of destroying 
disease-germs. It is to the second part that I would 
here call attention. Preliminary toa statement of the 
results of this part of Dr. Fischer’s work, a few facts 
in regard to the nature of the substance may not be 
out of place. 
Naphthaline, a carbohydrate of the formula C,,Hs, 
was first made in 1820, by Garden, from coal-tar. 
It is volatile at any temperature, melts at 79.2° C., 
boils at about 214° C., and has a specific gravity of 
about 1.1. Essentially insoluble in water, alkalies, 
and diluted acids, it is easily soluble in ether, hot 
alcohol, hot concentrated sulphuric acid, and in many 
volatile and rich oils. It is readily carried off with 
aqueous vapors; so that, in order to quickly disinfect 
a room, it is only necessary to heat a vessel with water 
in which naphthaline has been put.- The naphtha- 
line gas mixes very readily with atmospheric air, and 
is also readily taken up by water. It is not poisonous 
to man or to the higher animals, and, for surgical pur- 
poses, should be used chemically pure. The crude 
material is by far cheaper; and, upon inquiry, Dr. 
Fischer found that in London it can be obtained, 
without barrels, at 25 marks ($6) per 1,000 kilograms 
(about 2,200 pounds), in Paris at 100 francs, and in 
Cologne at about 45 marks (barrels included). The 
crude naphthaline contains more or less phenol and 
creosote, and is a stronger insecticide than the puri- 
fied article, but also more injurious to plants. Dr. 
Fischer used the purified naphthaline in his experi- 
ments on Phylloxera, but thinks that with some pre- 
