Page images

nifers it to the foetus in the womb, and produces an extention of parts; yet tince a placenta and an umbilical chord are by all thought effential to the effecting thele ends; and fince the cotyledons of plants, which include the corculum or first principle of the future plant, with which they communicate by means of tubes branched out into infinite ramifications, are wholly analogous to the placenta and umbilical chord of animals, we have great reafon to fuppofe that the embryo plant and the embryo animal are nourished and dilated in their dimenfions after the fame way. This analogy might be extended and confirmed by obferving that the lobes, within which the fœcundated germ is placed, are by putrefaction converted into a milky fluid, well adapted as an aliment to the tender ftate of the plant.

"Exfpiration and infpiration, a kind of larynx and lungs, perfpiration, imbibition, arteries, veins, lacteals, an organized body, and probably a circulating fluid appertain to vegetables as well as to animals. Life belongs alike to both kingdoms, and feems to depend upon the fame principle in both : ftop the motion of the fluids in an animal limb by a ftrong ligature, the limb mortifies beyond the ligature, and drops off; a branch of a tree under like circumftances, grows, dry, and rots away. Health and ficknefs are only other terms for tendencies to prolong or to abridge the period of life, and therefore must belong to both vegetables and animals, as being both poffeffed of life. An east wind, in our climate, by its lack of moisture, is prejudicial to both; both are fubject to be froft-bitten, and to confequent 'mortifications; both languifh in exceffive heats; both experience ex

travafations of juices from repletion, and pinings from inanition ; but can fuffer amputation of limbs without being deprived of life, and in a fimilar manner both form a callus; both are liable to contracting difeafes by infection; both are ftrengthened by air and motion: Alpine plants, and fuch as arc expofed to frequent agitation from winds, being far firmer and longer lived than thofe which grow in fhady groves, or hot houfes; both are incapable of affimilating to their proper fubftance all kinds of food; for fruits are found to tate of the foil, juft as the urine, and milk, and flefh, and bones of animals, often give indications of the particular pabulum with which they have been fed: both die of old age, from excefs of hunger or thirit, from external injuries, from intemperature of weather, or poifoned food.

"Seeds of various kinds retain their vegetative powers for many years: the vivification of the ova, from which the infects occafioning the fmut in corn, and the infuforia animalcula obfervable in water after the maceration in plants, probably proceed, may be eiteemed a fimilar phænomenon. It is not yet clearly decided amongst naturalifts, whether the feeds of mushrooms, of mucors, and of the whole clafs of fungi, be not in a tepid, humid trix, changed into vermicular animals, which lofe in a little time their power of fpontaneous motion, coalefce together, and grow up into thefe very fingular plants: the quickness of their increafe, and the irrefiftible force with which the mouldinefs propagates itself, and deftroys the texture of the bodies upon which it fixes, feem to point towards an animal nature.


"Different vegetables require different foils, as different animals


do different food for their fupport and well being: aquatics pine as ay in dry fandy grounds, and plants which love rocks and barren fituations, where they imbibe their chief nutriment from the air, become difeafed and putrid in rich bogs and fwamps.

There are aquatic animals which become iminovable and lifelefs when the rivulets in which they fubfifted happen to be dried up, but which recover their life and locomotive powers upon the defcent of rain in this circumftance they are analogous to the clafs of moles among vegetables, which, though they appear to be dried up, and ready to crumble into duft during the heats of fummer, yet recover their verdure and vegetable life in winter, or upon being put into a humid foil.

[ocr errors]

Trembley, Bonnet, and Spallanzani have vaftly amplified our views of nature; they have difcovered to us divers fpecies of animals, which may be cut into a variety of pieces without lofing their animal life, each piece growing up into a perfect animal of the fame kind the multiplication of vegetables by the planting of branches, fuckers, or joints of roots is a fimilar effect. The re-production of the legs of craw-fifh, lobsters, crabs, of the horns and heads of fnails, legs of lizards, of the bony legs and tails of falamanders, when by accident or defign they have been deprived of them; and the great difference in the time of the reproduction, according to the feafon of the year in which the limb is loft, are wonders in the animal kingdom, but wholly analogous to the repulJulation of trees after lopping.

"All plants, except thofe of the claffes monecia and diacia, are ermaphrodites; that is, they have

the male and female organs of generation within the fame empalement. Shell-fish, and fuch other animals as refemble vegetables in not being able to move far in fearch of mates, with which they might propagate their kind, are herma phrodites alfo: Reaumur hath prov ed that vine fretters do not want an union of fexes for the multiplication of their kind.

"From the conjunction of animals of different fpecies are pro duced hybrides, which in many cafes cannot propagate: botanifts have tried the experiment, and by fœcundating female flowers with the male duit of another fpecies, have produced hybridous plants, of an intermediate fhape, the feeds of which are barren and effete.

"Trees fhed their leaves as birds do their feathers, and hirfute animals their hair. At particular feafons the juices of vegetables move with fulness and vigour; at others they are lefs plentiful, and feem to ftagnate; and in this they resemble dormice, bats, frogs, and numberlefs other animals of cold blood, which lie torpid and deftitute of every fign of life during the winter time; the action of the lungs and of the heart being, if any, imperceptibly weak and languid.

"Few, if any animals can exist without a reciprocal fucceffion öf fleep and vigilance, and the younger the animal, the greater is its propenfity to fleep: the fame alternative feems neceffary for the health of feveral vegetables; a great variety of plants fold up their leaves, and feemingly compofe themselves to reft, in the night time, and this difpolition for fleep is more remarkable in young plants than in old ones; nor does it, as might be fufpected, depend upon the influence of light or heat, fince plants in hot houses,


where the heat is kept at the fame degree, fold up their leaves at a ftated time in the evening, and expand them in the morning, whether the light be let in upon them or not. It may deferve to be inquired, whether by a relaxation of fibres these plants become fubject to a more copious perfpiration during fleep than in their state of vigilance, as Sanctorius hath proved to be the cafe in animals.

"There is a great diverfity, but a regular fucceflion in the times, in which animals of different fpecies feel the ftrum, by which they are ftimulated to the propagation of their respective kinds; an order equally determined, is obfervable in the times of accomplishing the Sponfalia of plants. The periods of incubation in oviparous, and of geftation in viviparous animals are not more various in different fpecies, nor probably more definite in the fame, than the periods requisite for she germination and maturation of different feeds. By the influence of heat and cold, abundance and fcarcity of nourishment, the feafons of propagating may be fomewhat accelerated or retarded in animals as well as in vegetables: the effects of a cold ungenial fpring are as remarkable in the retardation of the procreative intercourfes of birds and beafts, as in the ftoppage of the leafing of trees, or the flowering of fhrubs. In a word, there are fo many circumstances in which the anatomy and phyfiology of fome plants agree with thofe of fome animals, that few, I believe, can be mentioned in which they difagree.

"When it is confidered that animals are either mediately or inmediately wholly nourished from vegetables, it might be expected, a priori, that the products obtainable by a chemical analysis from the two

kingdoms fhould be different rather in quantity than quality, and that we could not from thence difcover any criteria by which they might be diftinguished from one another: this obfervation is confirmed by experiment. Animals, it is true, in general yield a greater proportion of a volatile alkaline, than of an acid falt by diftillation; vegetables on the contrary abound in acid, and yield not any volatile afkali, unless with the laft degree of heat, or when they have undergone putrefaction: in aying this, I am aware that I differ from the opinion commonly received. Muftard feed, watercreffes, horfe radifh, and other plants of the tetradynamia clafs are generally faid to contain a volatile alkali already formed, and to yield it with the heat of boiling water; from none of thefe however could I ever obtain by that heat a phlegm which would give a precipitation with corrofive fublimate, the most indubitable teft of a fluid's containing even the minuteft portion of volatile alkali; the pungent fmell feems to have been mistaken here, as fir John Pringle hath well obferved the fitor to have been in the putrefaction of many animal fubftances, as proceeding from a volatile alkali; and which may, perhaps, be with greater truth attributed to a volatile oil, a fmall portion of which is fometimes procurable from pepperwort, by the heat of boiling water impreg nated with fea-falt. However, as fome animals, and fome parts of moft animals yield a portion of acid, and as moft vegetables, by a strong fire in clofe veffels, or when converted into foot, afford a volatile alkali, altogether fimilar to that ob tained from animal fubftances, we cannot from thefe circumstances

eftablish any diftinctive mark between the two kingdoms."


We have been favoured by the AUTHOR with the following original




Few weeks ago I received, from the archbishop of York, a fmall quantity of the bombax ceiba, or filk cotton of Sumatra, with a request that I would enquire whether it might not be applied to fome important ufes in the manufactures of Manchefter. The fpecimen was given to his Grace by Mr. Wm. Marsden, F. R. S. late fecretary to the prefident and council of Fort Marlborough, and author of a valuable work, entitled the Hiftory of Sumatra. I have fewn the cotton to feveral of our moft ingenious manufacturers, who unite in admiring its foftness, fineness, beauty, and filky glofs; but are apprehenfive, from the fhortnefs and extreme tendernefs of its filaments, that it is unfit for the operations of carding, fpinning, or weaving. But it occurred to me that in the manufacture of hats, no operation feems to be required, which would overtrain the texture of this delicate fubftance; that it is adapted to the reception of a bright and permanent dye; and that its fineness and foftnefs might render it a good fubftitute for bea

A gentleman, however, converfant in this branch of trade, to whom I fhewed the cotton, and communicated the foregoing conjectures, is of opinion that it has not fufficient firmnefs for matting together in the structure of a hat.

Notwithstanding thefe difcouragements, I am not yet convinced

that the Sumatra cotton might not, by a mixture with other fpecies, with filk, or with worited, be repdered useful to our manufactures. And poffibly its fibres may, when feparately employed, be fufficiently ftrengthened for the wheel or the foom, by undergoing a due prepas ration. Hairs of the fame length vary much in their powers of extenlion, when wetted with different fluids, as Dr. Bryan Robinson has proved. And may we not infer, from analogy, that the fame diverfity would take place in the filaments of cotton? The fact might eafily be afcertained; and I take the liberty of recommending the investigation of it to fome ingenious experimenter, interested in the improvement of our manufactures. la this undertaking three objects may be held in view: 1. To increase the powers of cohefion in the fibres of cotton, without proportionably augmenting their powers either of extenfion or elafticity. 2. To augment the power of extenfion, without affecting that of elasticity. 3. To increase the power of elafficity, in conjunction with that of extention. Different fubftances may be found to poffefs qualities adapted to these several ends, each of which may be appropriate to fome particular kind of manufacture.

Since the foregoing remarks were written, I have confulted Mr. Marsden's Hiftory of Sumatra, and

* See his Treatise on the Virtues and Operations of Medicines. Page 178.

fall transcribe from it, what he delivers concerning the bombax ceiba. "The filk cotton is allo

to be met with in every village. This is to appearance one of the "most beautiful raw materials the hand of nature has prefented. Its fineness, glofs, and delicate foftnefs render it, to the fight and touch, much fuperior to the la"bour of the filk worm; but, "owing to the fhortnefs and brittleness of the staple, it is citeemed ** unfit for the reel and loom; and is only applied to the unworthy purposes of ftuffing pillows, and mattraffes. Poffibly it has not undergone a fair trial in the hands of our ingenious artists; and we may yet fee it converted

"into a valuable manufacture.

[ocr errors]


grows in pods, from four to fix "inches long, which burst open

when ripe. The feeds entirely "refemble black pepper; but are "without taite. The tree is re"markable from the branches "growing out perfectly straight "and horizontal, and being always "three, torming equal angles at the "fame height. The diminutive "fhoots, likewife, grow flat; and the "feveral gradations of branches.ob"ferve the fame regularity to the "top. Some travellers have call"ed it the umbrella tree; but the "piece of furniture called a dumb "waiter, exhibits a more ftriking picture of it." (Hiftory of Su matrą, page 126.)

On the ACID of TAR,
[By the Same.]

AR, boiled to drynefs, with

out addition, yields an acid

Liquor, in confiderable quantity,
which the workmen injudicioufly
throw away; though an able che
mit informs us, he has known
a perfon in France fave by it many
thousand dollars *. I have late
ly procured feveral gallons of it,
from a large pitch manufactory at
Hull. It exceeds greatly in pun-
gency other vegetable acids; and I
am perfuaded that it might be em-
ployed to advantage, both in phar-
macy and the arts, as a cheap and
active menftruum. Such are its
corrofive powers, that I am inform-
ed, it foon proves destructive to the
large metallic veffels, in which it
is difilled. If thefe be of copper,


[ocr errors]

they bear about a year's working;
if made of tin, they are prefently
eaten into holes, like a honey-comb.
It is not easy to form an exact efti-
mate of the comparative ftrength of
different acids; but from feveral
experiments which I made, it ap
peared to me probable, that the
acid of tar is to the fp. vitriol. fort.
in this refpect, as one to fourteen,
For five drops of the former, and
feventy drops of the latter gave the
like degree of pungency to equal
portions of water; and feemed to
be faturated with equal quantities
of fixed alkali. A thin piece of
lead, weighing twenty-three grains,
was fufpended by a string, feveral
weeks, in two ounces of the acid of
The menftruum gradually

• See Newman's Chemistry by Lewis, page 288,

[ocr errors]
« PreviousContinue »