had been discovered. I have tried most of those plants recommended by her, and several others, without the fmalleft appearance of fuccefs. The worms would fometimes cat them, but whenever they did, it always proved prejudicial to them, and generally destructive.

"In the valuable paper fubjoined to Mis. William's Letters, written by the honourable Daines Barring ton, it is hinted that a fuccedaneum for mulberry-leaves might be difcovered by examining what infects, in this country, feed upon the mulberry, in common with other plants; prefuming from thence, if any hould be found, that thofe plants would resemble each other in their flavour and nutritive qualities. Could any infects be found in the circumstances before mentioned, it might poffibly lead to fuch a difcovery. But your correfpondent mifs Rhodes, has remarked (and I have myfelt noticed the fame) that no indigenous infect of this country preys on the leaves of the mulberry; not even the race of the aphides, thofe almost univerfal plunderers.

"As a farther direction to a refearch of this kind, the observation of botanifts may be adduced, that plants of the fame natural clafs and order have a near refemblance in their virtues and qualities. This clue would lead us to only a few plants of the native growth of this ifland, which fand in the above degrees of affinity to the mulberry: and thefe are, the nettle, the boxtree, the birch-tree, and the alder. The most likely of thefe I fhould fufpect would be the birch: for I have not tried either of them, neither do I recommend the experiment to others; as I think all experiments with a view to procure a fubflitute for the mulberry quite unnecellary. For what neceffity

can there be for ranging in quest of other food, when the mulberrytree itself, the acknowledged proper and natural :ood of thefe infects, will thrive and profper in this country as well as most other trees. In very poor foils indeed they grow fparingly. But in foils tolerably rich, either thofe that are naturally fo, or enriched by art, they vege tate with all the luxuriance that can be wifhed. I at prefent know the owner of two mulberry-trees, which have not been planted more than fifteen or fixteen years from the layers, which, in my opinion, would each of them have maintained for thefe two or three years past, near three thoufand worms in a feafon.

"The chief reafon alledged for the neceffity of finding out a fubftitute for mulberry leaves, is, that thefe leaves are not produced early enough in this climate to become the food of the infant worms. It is well known, that the leaves of the mulberry-tree, feldom begin to unfold themfelves before the latter end of May, or the beginning of June. It is likewife a matter of noto' riety, that thofe few filk worms which have as yet been bred in this ifland, have moftly been hatched by the beginning of May, or even earlier. From hence there has been fuppofed a neceffity for providing fome more early vegetating plant for their food, before the leaves of that tree are ready for them. That no fuch necellity exifts is to me very apparent. Is it not natural to conclude, that the conititution of the air, refpecting warmth, fhould at one and the fame time expand the leaf, and protrude the infect which was intended by all-wife providence to inhabit and feed on that leaf? This, we may obferve is the conftant course of nature, with respect to all other

infects

infects and their food, We have every reason to fuppose that this is the cafe with the filk worms, and the mulberry leaves, in thofe countries where both are indigenous: and I have not the fhadow of a doubt that this effect would naturally and invariably obtain as well in this climate as any other, did not human imprudence interpofe to prevent it, and art obftruct the intention of nature. The eggs of filk worms, have in this country, been generally configned to the care of young people, and chiefly thole of the female fex. They have been preserved in bure.us, and chests of drawers, in rooms where fiies have been conftantly kept during the winter featon. In the fpring, as foon as the influence of the fun began to be powerful, the eagernefs of youthful curiosity, has caufed them to be removed to windows, where the fun exerted its full power and in this fituation they have been generally forced into exiflence, within a few hours, in a featon, when the temperature of the air was unfit for them, and when their proper food could not be procured.

66

One of your late correfpondents on this fubject, Mrs. Williams, has proved that the hatching of the eggs may be accelerated, and has averred, that it is even poffible to hatch them in the midst of winter: the other, mifs Rhodes, has experienced that it may be retarded beyond the ufual time, fince in her fecond letter, dated the 24th of Augut, 1785, the informs you, that her filk worms eggs, in that year, were not hatched until the fecond of June, and not even then, with out being placed in the funfhine. 1 have this feafon retarded it longer, until the middle of June; when likewite it was effected, by expofing .1787.

the eggs to the vivifying influence of that great fource of life and light. There cannot then, I think, be the least doubt that the eggs of filk worms may be hatched at almost any time. And I fhould recommend it to every person who fhall hereafter engage in the businefs of breeding theie worms, unlefs it be for mere amufement, to take care that this effect does not take place until the mulberry-tree is nearly in full leaf.

"There are three reafons which appear to me of great weight for recommending the full foliation of the mulberry-tree, as the regulator in this matter. The first is, that there may be a fufficient ftore of their natural food ready for the young worms, as foon as they come forth from the eggs, which will preclude all neceffity for feeking after other food. A fecond is, that thefe worms being originally natives of a warm climate, may be fure to be brought to life when the air is of a temperature congenial, and agreeable to them; fince it is a general obfervation among gardeners, that when the mulberry-tree begins to expand its foliage, it is a certain fign of the near approach of fine, warm, fettled weather. A third reafon is, that the mulberry-trees may be permitted to put forth a good quantity of leaves before any of them are plucked, that fo they may not fuffer fo much in health from that operation, as they otherwife would do, and may be equal to the fupport of a much larger flock of infects. For it is certain, that the leaves are as neceffary to the life of a vegetable, as the skin or the lungs are to that of an animal. If therefore most of the young leaves are immediately cropped off, as foon as they are put forth, the confequence undoubtedly

M

will

will be, that the tree will be fo weakened and retarded in putting forth its leaves, that it will not produce near the quantity it would otherwife have done, and if this ufage be often repeated, will inevit ably be destroyed To this laft mentioned circumftance I impute it, that the tender heart of your fair Shropshire correfpondent furfered thofe mortifying apprehenfious which he has fo feelingly defcribed in her first leter of your late publication; and that to confiderable a number as twelve large mulberry-trees were farcely adequate to the maintenance of ten thoufand worms.

"If what I have afferted in the beginning of this letter be a fact, that no other vegetable can ever be fubftituted, with advantage, as the food of filk worms; it will follow, that before any attempt to breed them upon an extenfive plan can fucceed, it is abfolutely neceffary that the mulberry-trees fhould become much more numerous than they are at prefent. Of this the fociety, it fhould feem, have long been convinced; fince they have, through a fucceffion of years, prof. fered rewards for increafing their number; but hitherto, I believe without fuccefs.

"From the premiums No. 40, and 41, in the clafs of Agriculture, as they now ftand in the last volume, I was led to apprehend, that the fociety had given up the matter in defpair; and that thofe premiams were intended to be difcon tinued. I hope my apprehentions will prove groundlefs; and to have been occafioned merely by typo. graphical error.

If it would not fubject me to the imputation of impertinence or prefumption, I would recommend It to them to multiply their premi

ums on this head, and to be parti cularly liberal in their offers.

"There are three modes of raiíing mulberry-trees, to which we are directed by nursery-men. The raising them from layers, from feed, and from cuttings. The chief method now in practice for thole few trees there is a demand for, is by layers. But this is fuppofed to be an infufficient mode, where great numbers are wanting And yet clm trees, which are planted is fuch numbers in this country, a e chiefly propagated by this method. The mode of raifing them from feed, is not only tedious but uncer tain; as the feed feldom ripens fufficiently in this climate, and the dependence on foreign feeds of any kind is extren.ely precarious. The late premiums of the fociety have refpected only the last method, namely, that of raiting them from cuttings: this would be doubtle s, the most advifeable method for rifing a large number of trees in a fhort time, provided the cuttings of the mulberry-tree could be made to take root as readily as the cuttings of willow, poplar, and fome other trees. This however is not the cafe, for with the greatest care many of these cuttings will not grow, unless affifted by artificial heat.

"I have taken notice, that whenever the branches of a fig-tree have been fometimes inclofed in the fhreds, by which they are ufually tacked to the wall after pruning, abundance of budding roots are generally put forth. From henee I furmised, that cuttings of any trees might probably be prepare for taking root more certainly and expeditiously, by tying a thread of old woolen cloth or fuch like fubfance, pretty tight round every fhoot that is intended for a cutting,

bales of filk imported from abroad, is not the natural production of the filk-worm, but chiefly the addition of art: and that the filk when received, is oftentimes fo highly ftiffened, that the workmen are obliged to ditcharge much of the gum, by diluting it in water, before they can reel the filk off from the fkein, or manufacture it any way whatever. I have tried the experiment of reeling off the coccoons in boiling water; it has a good effect in diffolv ing the natural gluten, which caufes the web to part more freely; but I was never fo fortunate as to find the lives of the infects preferved after paffing through this fevere ordeal. The most troublefome office in the bufinefs of breeding filk worms, is the cleanfing them. This in the

common mode, is a tedious and difagreeable task, as well as incommodious, if not injurious, to the worms. Mifs Rhodes did not think this ope- ) ration neceffary oftener than once a week. It has appeared to me to be abfolutely neceffary to the health of the infects, when they are full grown, or nearly fo, that it should be performed at least once a day. I have the idea of a fimple apparatus, whereby I imagine this obftacle will be totally removed, as well as fome other inconveniences, which I mean to get realized before the next breeding feafon. Should it please me fo well when reduced to practice, as it does at prefent in theory, I fhall take the liberty to fend you either a model or defcription of it."

"TA

AKE an ounce of white wax, and the fame weight of gum maftick in lachrymæ, that is, as it comes from the tree, which muft be reduced to a coarfe powder. Put the wax in a glazed earthen veffel, over a very flow fire, and when it, is quite diffolved, ftrew in the maftick, a little at a time, flirring the wax continually, until the whole quantity of gum is perfectly melted, and incorporated; then throw the paste into cold water, and when it is hard, fake it out of the water, wipe it dry, and beat it in one of Mr. Wedgwood's mortars, obfervving to pound it at first in a linen cloth to abforb fome drops of water that will remain in the pafte, and would prevent the poffibility of re

ducing it to a powder, which must be fo fine as to pafs through a thick gauze. It should be pounded in a cold place and but a little while at a time, as after long beating, the friction will in a degree foften the wax and gum, and instead of their becoming a powder they will return to a pafte.

"Make fome strong gum arabick water, and when you paint, take a little of the powder, fome colour, and mix them together with the gum-water. Light colours require but a fmall quantity of the powder, but more of it must be put in proportion to the body and darkness of the colours; and to black, there fhould be almost as much of the powder as colour.