number of species is remarkable. A few miles of coast, without the aid
of storms, and without dredging, yielded 450 species. In the small bay
of Port Royal, 350 marine species were found. A pint of sand, taken
from a surface three yards long, contained 110 species. Probably there
are 350 or 400 specimens of land shells, and two or three times as
many of marine species. Extensive districts occur, however, which are
nearly destitute of land or marine shells. They are accumulated in
favourable stations.
The difference in the extent of the distribution of the marine and of
the terrestrial species is remarkable. A majority of the marine
species are known to occur in the other islands; probably not more
than 10 or 15 per cent. of them will be found to be peculiar to
Jamaica. But of the land shells, 95 per cent. are peculiar to the
island. The limited distribution of the terrestrial species is
remarkable. A few are generally distributed, but a large number are
limited to districts of a few miles in diameter; and several, although
occurring abundantly, could be found only within the space of a few
rods. Only seventeen fresh-water species were found. Favourable
stations for fresh-water species are rare.
In respect of the number of individuals of mollusca in Jamaica, as
compared with more northern latitudes, the rule so obvious in the
class of fishes is not applicable to the same extent. Of fishes, the
species are much more numerous, but individuals much less so. Of the
mollusca, the total number of individuals is about the same as in this
latitude, and the number of species represented by a profusion of
individuals is about the same. But the number of species not occurring
abundantly is much greater, so that the average of individuals to all
the species is less than in this latitude. From a comparison of the
laws of distribution of the marine and terrestrial species in the
Antilles, it follows that the number of the latter must exceed that of
the former. With the insular distribution of the terrestrial species
may be associated the fact, that the coral reefs are all fringing, for
both facts are connected with the geological fact, that these islands
are in a process of elevation.--Professor ADAMS before the American
Association.--_American Annual of Scientific Discovery_, p. 334.
14. _Metamorphoses of the Lepidoptera._--Professor Agassiz said that
he had, during the past season, been studying the metamorphoses of the
Lepidoptera, and, to his great surprise, he had found that one stage
in the transformation of these insects has been overlooked by
naturalists. We knew the Lepidoptera in three conditions,--that of the
worm, furnished with jaws and jointed, the chrysalis, and the perfect
insect with four wings. The change not before described, which he had
noticed, is somewhat concealed under the skin of the caterpillar. The
animal at a certain period swells at the thoracic region, and becomes
extremely sensitive to the touch in this part, the skin being, in
fact, in a state of inflammation. On cutting open the skin at this
place, Professor Agassiz found beneath it a four-winged insect, before
it had passed into the chrysalis state. The wings were long enough to
extend half the length of the perfect insect. The posterior pair he
found to be membraneous bags, somewhat flattened, like the respiratory
vesicles of marine worms, with distinct ribs, which are blood-vessels.
The anterior pair are also bags, with their upper half stiff and
inflexible, like the elytra of coleoptera. The legs are tubular, but
not joined, as in the perfect insect. The jaws are changed into two
long tubes, which are bent backwards, as are also the antennæ. In the
chrysalis, the wings are flattened and soldered together, as are the
legs and sucking-tubes, which are bent backwards. The order of
development of the different parts and the coleopterous condition at
an incomplete stage, show that naturalists have been in error in
placing chewing insects, as the coleoptera, above the sucking insects.
The order should be reversed. Professor Agassiz said that he had
confirmed his observations in many specimens, by examining them just
at the moment when the skin begins to split on the back.--_American
Annual of Scientific Discovery_, p. 327.
15. _On the Zoological Character of Young Mammalia._--At the meeting
of the American Association for the Promotion of Science, Professor
Agassiz remarked, that zoologists have, in their investigations,
constantly neglected one side of their subject, which, when properly
considered, will throw a great amount of new light on their
investigations. Studying animals, in general, it has been the habit to
investigate them in their full grown condition, and scarcely ever to
look back for their characters in earlier periods of life. We scarcely
ever find, in a book of natural history, a hint as to the difference
which exists in the young and old. Perhaps in birds, the colour of the
young may be noticed; and it is generally known, that the young
resemble the female more than the male; but as to precise
investigation of the subject, we are deficient. But if the early
stages of life have been neglected, there is one period in the history
of animals which has been thoroughly investigated, for the last
twenty-five years,--embryology. The changes which take place within
the egg itself, and which give rise to the new individual, have been
thoroughly examined; but, after the formation of the new being, the
changes in its form which it passes through, up to its full grown
condition, have been neglected. It had been his object to investigate
this subject, because he had been struck with the deficiency there is
on this point in our works; and in making this investigation, he had
found that the young animals, in almost all classes, differ widely
from what they are in their full-grown condition. For instance, a
young bat, a young bird, or a young snake, at a certain period of
their growth within the egg, resemble each other so much, that he
would defy the most able zoologist of our day to distinguish between a
robin and a bat, or between a robin and a snake. There is something of
high significance in this fact. There is something common to all
these. There is a thought behind these material phenomena, which shews
that they are all combined under one rule, and that they only come
under different laws of development, to assume, finally, different
shapes, according to the object for which they were introduced.
There is a period of life, in which, whatever may be the final form of
their organs of locomotion, whatever may be the final difference
between the anterior and posterior extremities, vertebrated animals
have uniform legs, in the shape of little paddles or fins. This is the
case with lizards as well as birds. A robin's wing and a robin's leg,
which are so different from a bat's wing and a bat's leg, do not
essentially differ when young from the leg and arm of a bat. Wherever
we observe combined fingers preserving this condition, we have a
decided indication that such animals rank lower in the group to which
they belong. This is all-important, as we are enabled at once to group
animals which are otherwise allied, in a natural series, as soon as we
know whether they have combined or divided fingers. And the degree of
division to which the legs rise in their development is a safe guide
in our classification. Look, for instance, at the legs of dogs and
cats, in which the fingers are completely separated, and so elongated,
that the animals walk naturally upon tip-toe, and compare them with
others, bears, for instance, which walk upon the whole sole of the
foot; and, again, with those of seals or bats, which remain united,
and constitute either fins or a wing.
There are other reasons sufficient to convince us that the order of
arrangement which he had assigned them, according the development of
the fingers, is justified by the state of development of the other
organs of the mammalia, and especially of their higher organs and
intellectual faculties and instincts. And I will also add, says
Professor Agassiz, that mankind are not excluded from this connection,
but, in common with other vertebrata, we are all at one stage of
existence provided with paddles or fins, which are afterwards
developed into legs and arms.--_American Annual of Scientific
Discovery_, p. 324.
16. _The Manatus or Sea Cow, the Embryonic Type of the
Pachydermata?_--Professor Agassiz thinks that the Manati have been
improperly considered cetaceans: they differ from them in the form of
the skull, which is elongated, and in the position of the nostrils,
which are in front. On the other hand, the skull resembles that of the
elephant in front (particularly when seen from above), in some of the
details of the facial bones, which are not like those of the cetacea,
in the palatine bones, the arrangement of the teeth, and in the curve
of the lower jaw. Professor Agassiz, believed this to be the true
embryonic type of the Pachydermata.--_American Annual of Scientific
Discovery_, p. 313.
17. _Fossil Elephant and Mastodon from Africa._--M. Gervais
communicated to the French Academy, on March 12th, that he had just
received from Algiers, a drawing of the molar tooth of a fossil
elephant, whose genus is very easily recognised, and which indicates a
species more resembling those found in a fossil state in Europe, than
the present African elephant. This tooth was found at Cherchell, in
the province of Oran. Sicily has hitherto been the southernmost point
on the Mediterranean where the fossil elephant has been found.
At the same time, he also mentioned the discovery, near Constantine,
of some fossil remains of mastodons. Though fossil remains of this
animal have been previously found in all the other portions of the
world, these are the first discovered in Africa. The remains found are
a tooth and a rib, and, as far as can be judged from a drawing, they
belonged to an animal more resembling the mastodon brevirostris, or
the arvernensis, than the mastodon angustodens.--_American Journal of
Scientific Discovery_, p. 287.
18. _Cauterization in the case of Poisonous Bites._--In the _Comptes
Rendus_ for January 8th, we find an article by M. Parchappe,
containing the result of his observations on the question, whether the
spread of poison produced by a bite can be prevented by cauterizing.
He was induced to examine into this subject, because M. Renard had
stated that cauterization was found to have no effect when applied
even within five minutes after the bite in the cure of one sort of
virus, and within one hour in that of another. These results, he was
aware, though derived from experiments upon animals, would weaken the
confidence of physicians and patients in the only mode that medicine
possesses of preventing the bad effect of a bite from any poisonous
animal, where, as is generally the case, some considerable time must
elapse before the remedy can be applied. M. Parchappe, accordingly,
made several experiments upon dogs, with an extract of nux vomica, all
of which go to confirm him in ascribing to cauterization, a power even
greater than that commonly allowed it.--"From these experiments it
results, that the immediate amputation or destruction in the living
portion with which the extract of nux vomica has come in contact, has
the power of preventing the bad effects of the poison, even when it
has been in contact for some time." The author is aware, that there is
considerable difference between the virus of animals, and the
substance used by him, with reference to their direct and remote
effects, but thinks that every one must admit that there is a great
_analogy_ between them, is of the opinion, that in both cases the
poison remains in the bitten part for a considerable time before it is
transmitted to the rest of the body, and that cauterizing should be
adopted in all cases where a poisonous bite is even suspected.
19. _Dental Parasites._--At a meeting of the American Academy,
December 1849, a paper was read by Dr H. J. Bowditch, on the animal
and vegetable parasites infesting the teeth, with the effects of
different agents in causing their removal and destruction.
Microscopical examinations had been made of the matter deposited on
the teeth and gums of more than forty individuals, selected from all
classes of society, in every variety of bodily condition, and in
nearly every case animal and vegetable parasites in great numbers had
been discovered. Of the animal parasites there were three or four
species, and of the vegetable one or two. In fact, the only persons
whose mouths were found to be completely free from them cleansed their
teeth four times daily, using soap once. One or two of these
individuals also passed a thread between the teeth to cleanse them
more effectually. In all cases the number of the parasites were
greater in proportion to the neglect of cleanliness.
The effect of the application of various agents was also noticed.
Tobacco juice and smoke did not impair their vitality in the least.
The same was also true of the chlorine tooth-wash, of pulverized bark,
of soda, ammonia, and various other popular detergents. The
application of soap, however, appeared to destroy them instantly. We
may hence infer that this is the best and most proper specific for
cleansing the teeth. In all cases where it has been tried, it receives
unqualified commendation. It may also be proper to add, that none but
the purest white soap, free from all discolorations, should be
used.--_American Annual of Scientific Discovery_, p. 320.
ARTS.
20. _The Steamboat New World._--Every year sees some new steamboat
constructed, which surpasses in size, magnificence, or speed those
previously made. There is no doubt that the mechanics of this country
excel those of any other in their inland steamboats, and it is also
probable that in a few years the same can be said of our sea-going
steamships, though it must be allowed that those hitherto produced
are, with few exceptions, decided failures. During the present year,
the new steamboat "New World" has commenced running. She is said to be
the longest boat ever put on the stocks in this country, and the
longest afloat in the world. Her length is 337 feet; extreme width, 69
feet; the engine is 76 feet in cylinder, 15 feet in stroke, and the
wheels of iron, 46 feet in diameter. She draws 4½ feet of water. The
engine is a low pressure one, and though the boat is so very long she
obeys the helm with great readiness. Her decorations are all of the
most superb and costly character.
If we even attain any greater speed either in our inland or sea-going
steam-vessels, it will be principally by enlarging their size. Though
some improvements will doubtless be made in the engines and in the
models of the vessels, yet the great gain will be by increasing the
tonnage, for the reason that the size, and consequent room for engines
and coal, increases much faster than does the opposition caused by the
water and the air.--_American Annual of Scientific Discovery_, p. 30.
21. _Use of Parachutes in Mines._--It is well known that vertical
ladders for descending into deep mines are very fatiguing, so that the
miners prefer to trust themselves to baskets suspended by ropes, and
in many cases the baskets are the only means provided for descending
and ascending. But accidents frequently occur from the breaking of the
ropes, in spite of all the precautions that can be taken to prevent
it. The _Brussels Herald_ states that some experiments have lately
been made on a large scale in Belgium with a contrivance intended to
remedy this evil. The basket or cuffert is so made, that, in case the
rope breaks, it immediately springs open, forming a sort of parachute,
which is held suspended in the air by means of the strong current
which, it is well known, is always rushing up from mines, owing to the
temperature below being higher than that above. The effect of this
apparatus was shown before a numerous company, several miners
entrusting themselves to the basket, which was so arranged that at a
certain point the rope broke; they were sustained in the air by the
open basket, so that the experiments were entirely satisfactory.
22. _Adulteration of Drugs._--At a meeting of the New York Academy of
Medicine, June 1849, an elaborate report was presented by Dr M. J.
Bailey, on the practical operation of the law prohibiting the
importation of adulterated and spurious drugs, medicines, &c.
The report states, that since the law took effect, July 1848, over
90,000 lbs. of drugs of various kinds have been rejected and condemned
in the ports of the United States. Of these, 34,000 lbs. was included
under the comprehensive title of Peruvian bark, 16,343 lbs. rhubarb
root, 11,707 lbs. jalap root, about 2000 lbs. senna, and about 15,000
lbs. of other drugs. The agitation of the bill which preceded the
passage of the law had its effect abroad, and the supply of
adulterated drugs from foreign markets has greatly decreased. The
domestic supply, has on the contrary increased. Within a recent
period, quinine in considerable quantities has been found in the
market, adulterated to the extent of some twenty or twenty-five per
cent. These frauds were undoubtedly perpetrated by or among our own
people. The material used for the adulteration of the quinine was
found, on analysis, to be _mannite and sulphate of barites_, in nearly
equal weights. The latter article has long been used for this purpose,
but not until lately has _mannite_ been detected in the sulphate of
quinine. It seems to have been ingeniously substituted for salicine,
and a somewhat similar substance prepared from the poplar bark; which
articles have heretofore been extensively used for like purposes. The
ingenuity consists in the fact, that it is much more difficult to
detect the adulterations when effected by the admixture of _mannite_,
than when by the admixture of salicine, &c., while the former can be
furnished for less than one-fourth of the expense of the latter.
For some years past an extensive chemical establishment has been in
operation at Brussels, in Belgium, built up at great expense and care,
and expressly designed for the manufacture, on a large scale, of
imitations of all the most important foreign chemical preparations
used in medicine; while, at the same time, an agent was travelling in
this country making sales, and soliciting orders in all the principal
towns on our sea-board. The articles were prepared and put up with
consummate skill and neatness; and the imitation was so perfect that
it was impossible for the unsuspecting purchaser to distinguish them
from the genuine, notwithstanding that, in some instances, they did
not contain over five per cent. of the substances represented by the
label. Since the law went into effect at the port of New York, not a
single package has been presented for entry. Dr Bailey states,
however, that he has been informed that the persons formerly connected
with the Brussels firm, are now in this country engaged in the same
iniquitous business; hence the adulterations spoken of.--_Annual of
Scientific Discovery_, p. 188.
23. _To restore Decayed Ivory._--Mr Layard, in his explorations among
the ruins of Nineveh, discovered some splendid works of art carved in
ivory, which he forwarded to England. When they arrived there, it was
discovered that the ivory was crumbling to pieces very rapidly.
Professor Owen was consulted to know if there was any means of
preventing the entire loss of these specimens of ancient art, and he
came to the conclusion that the decay was owing to the loss of the
albumen in the ivory, and therefore recommended that the articles be
boiled in a solution of albumen. The experiment was tried, with
complete success, and the ivory has been rendered as firm and solid as
when it was first entombed.
24. _Ivory as an Article of Manufacture._--There are several sorts of
ivory, differing from each other in composition, durability, external
appearance, and value. The principal sources from which ivory is
derived are the western coast of Africa and Hindostan: Camaroo ivory
is considered the best, on account of its colour and transparency. In
some of the best tusks the transparency can be discovered even on the
outside. The manufacturers have a process by which they make poor
ivory transparent, but it lasts only for a short time. A third kind of
ivory, called the Egyptian, has lately been introduced, which is
considerably lower in price than the Indian, but in working there is
much waste. By an analysis, the African ivory shows a proportion of
animal to earthy matter of 101 to 100; the Indian, 76 to 100; and the
Egyptians, 70 to 100. The value of ivory consumed in Sheffield, where
it is much used in making handles for cutlery, is very great, and
nearly 500 persons are employed in working it up. To make up the
weight of 180 tons consumed in that place, there must be about 45,000
tusks, whose average weight is nine pounds each, though some weigh
from 60 to 100 pounds. According to this, the number of elephants
killed every year is 22,500; but allowing that some tusks are cast,
and some animals die, it may be fairly estimated that 18,000 are
killed every year merely for their ivory, which is contrary to the
usual belief that the ivory used comes from the tusks cast by living
elephants. These estimates, it will be seen, are for Sheffield merely.
25. _Flexible Ivory._--M. Charriere, a manufacturer of surgical
instruments in Paris, has for some time been in the habit of rendering
flexible the ivory which he uses in making tubes, probes, and other
instruments. He avails himself of a fact which has long been known,
that when bones are subjected to the action of hydrochloric acid, the
phosphate of lime, which forms one of their component parts, is
extracted, and thus bones retain their original form and acquire great
flexibility. M. Charriere, after giving to the pieces of ivory the
required form and polish, steeps them in acid alone, or in acid
partially diluted with water, and they thus become supple, flexible,
elastic, and of a slightly yellowish colour. In the course of drying,
the ivory becomes hard and inflexible again, but its flexibility can
be at once restored by wetting it either by surrounding it with a
piece of wet linen, or by placing sponge in the cavities of the
pieces. Some pieces of ivory have been kept in a flexible state in the
acidulated water for a week, and they were neither changed, nor
injured, nor too much softened, nor had they acquired any taste or
disagreeable smell.
26. _Air-Whistle._--Mr C. Daboll, of New London, Connecticut, has
invented a whistle that speaks with a most "miraculous organ" whenever
its services are required for the purpose of alarm or warning. It is
designed for the use of vessels at sea or on the coast, as on our
eastern shores, where dense fogs prevail, and vessels are liable to
come in collision before they are conscious of each other's approach.
Its great advantage is its power of communicating sounds for a
distance of from 4 to 5 miles, far exceeding the largest bells. An
experimental one has been placed on Bartlett's Reef, and the pilot of
the "Lawrence" states that he has heard it when about 4 miles off from
Bartlett's Reef, _against the wind_, which was blowing quite fresh at
the time. This was on a clear day, and when the whistle was blown at
his request, and also by advice of the inventor, so that the distance
might be marked. It is probable that, under the same circumstances,
the tones of a bell could not have been heard more than from one half
to three-fourths of a mile. The pilot of the steamer "Knickerbocker"
reports, that he _made the whistle_ during a dense fog, thirteen
minutes' running-time of the steamer, before coming up with the
station where it is located. He therefore must have been some four or
five miles distant from it when he heard it.