Waters which reft on the foil become hurtful, 1. By excefs; for too great moifture hinders plants from attaining the end of their vegetation, which is, the perfecting of their feeds; for what they do produce then, being too full of water, fhrive when dried, and are easily deftroyed by too great cold. Hence alfo it is, that wet feafons do not yield the mcft plentiful harvefts. Befides, too great a quantity of water entering into the veffels of plants, diftends them too much, and fometimes burfts them; and this the more readily, the more the veffels refift the diftending force. Too great abundance of water likewife forms a vitiated thin food, which either putrefies or becomes acid by the heat of the fun, as we fee in ftagnating water and for this reafon it is that fuch places are barren. To this alfo it is partly or wholly owing, that plants which grow in land abounding too much in moisture, are feized with a diforder refembling a mortification in live bodies; and hence too, probably, the roughness and fcabbed appearance of their stems and leaves. When land has been too wet, even rich foils, the marley or clayey, it becomes hard if a drought fucceeds, and that hinders the roots from piercing into it; and laftly, too much water prevents the accefs of the air to the roots. It is evident then, on these accounts, that too great a quantity of water deftroys the natural progreffion of the growth of plants, and rather impedes than promotes vegetation. A want of water is hurtful, because the earth becomes too dry and burning. Warmth diffipates the moisture in the earth, and the earth being as it were baked by the rays of the fun, burns up the roots of plants. Land which has been marled, or improved by alkaline falts, lime, or dung not rotted fuf. ficiently, is most liable to this ca lamity. In fhort, it neceffarily follows, that a want of water will deprive plants of every advantage before mentioned as arifing from the due quantity of water. Excefs of rain, or of water from the atmosphere, is hurtful, becaufe it leffens the warmth in the earth, and in the veffels of plants and hence it is, that, in very rainy feafons, plants do not grow but inftead of that deep green, which denotes their healthy ftate, become of a pale colour, and rather diminish in fize, especially if the rain is attended with cold. The earth is rendered fo loofe, that the roots have no firm fteady holding. The ftems are fo much weakened, that they are apt to fall, efpecially when they are grown large and in rich fields, whereby the feed, and indeed the whole plant, is hurt and rotted; and if these rains fall when the plants are in bloom, their farina is washed away, fo that there is no impregnation, and confequently no grain. Whoever confiders the utility of rain, in dae quantity, for promoting of vegetation, will be fenfible that the want of it, by depriving plants of all the benefits of that water, must be highly prejudicial. It may perhaps be alleged from what has been here faid, that if water is the fule food of plants,_no land can ever become barren. But this objection cannot be properly answered, till we have fhewn what advantages arife from culture, and other means of enriching the earth. Ufeful . Useful or curious Projects, Difcoveries, [Received March 9, 1768.] A Letter from John Ellis, Efq; F. R. S. to the Prefident, on the fuccefs of his Experiments for preferving Acorns for a whole Year without planting them, fo as to be in a ftate fit for vegetation, with a view to bring over fome of the moft valuable feeds from the EaftIndies, to plant for the benefit of our American colonies. [Read March 10, 1768.] HAVING discovered that the difappointment, which I met with about a year ago, in attempt ing to preferve through the feafon fome ever-green oak acorns and feme chefnuts in wax, was owing to their being unfit for vegetation at the time of my inclofing them I refolved in my next attempt to try only fuch as I was perfuaded were found and fresh. Fortunately, my curious and learned friend, the Right Honour able Sir Thomas Sewell, Mafter of the Rolls, hearing of my diftrefs, offered to procure me fome excellent acorns of the English oak, part of a parcel he had been fowing at his feat at Otterfhaw near Chert fey in Surrey; thefe he was fo obliging to fend me the zoth of February, 1767; part of them I fowed immediately under the win. dows of my chambers, in the kitchen garden of Gray's-Inn: and on the 22d of the fame month I inclosed about thirty-fix of them in bees-wax. Most of those that I had fown in the garden came up in June following 1767, and by the middle of September were fix inches high, This gave me fome hopes that I fhould not labour in vain, as I had done before; for part of the fame parcel of ever-green oak acorns which failed, I had given to Sir Thomas Sewell the year before to fow, and he affures me that not one of them came up with him. I likewife difcovered, though too late, that the Spanish chefnuts, which failed, had been kiln-dried, this is a common practice in Spain, to prevent their fprouting by the damp heat in the hold of the fhip. I fhould not, my lord, be fo par ticular in explaining the cause of my disappointment, but to fhew, the care that is neceffary to be taken by perfons abroad in the choice of the feeds, as well as the ftate they ought to be in, if they expect they fhould anfwer the great end we propofe. obferve Before I mention the method in which I treated these acorns, I muft to your Lordship, that though I have formerly been fo fuccefsful as to preferve both acorns and chefnuts for the fpace of a year in bees-wax, feveral of which have afterwards vegetated, and fome of them are now grown into trees; trees; yet I always found that many of them were rotten when they were taken out of the wax; which made me fufpect that it was owing to the too great heat of the melted wax, that fo many of them were deftroyed. This put me on thinking of the following method to guard the feeds to be preferved, from too great heat, which I have the pleasure to fhew your Lordship, and the reft of the Royal Society, the good effects of. After I had chofen out the faireft acorns, laying afide fuch as had fpecks proceeding from the wounds of infects, I wiped them very clean till they were quite bright, for fear of any condenfed perfpiration on the furface, which, if inclofed, would turn to mouldinefs. I then poured fome, melted bees-wax into a china plate, about half an inch deep, and foon as the wax was cool, but ftill very pliable, I cut as out with a penknife as much would inclofe one acorn; this I wrapped round it, rolling it between my hands, till the edges of the wax were perfectly united in the fame manner I covered about thirty-fix of them with all the caution in my power, fo that after they had been fet to harden I could not perceive the leaft crack in them. When they were quite cold and hard, I prepared an oval chip box of feven inches long, four and a half broad, and three and a half deep; into this I poured melted bees-wax to the depth of an inch and half; and when I could bear my finger in it, I laid the covered acorns at the bottom in rows, as clofe as I could together; afterwards other rows over them, till the box was full; and when the firft wax began to cool, I poured fome wax that was barely fluid over the uppermost acorns, till they were I have juft now, my Lord, had ! RECEIVED December 5, 1767, I RECEIVE MDecember 5, 17672 tish Museum, a parcel of acorns preferved in wax (the quantity of acorns which I received was thirtyfour); and according to your de fire and direction they were fowed, as foon as I received them, into a fandy light loom. I placed the pots with the acorns under a frame, where they remained till January the 28th. I then took the pots with the acorns out of the frame, and placed them near a window, in one of our large airy floves, where they have remained ever fince: according to your defire, they fhall ciety's houfe. I think the gentle. men of that honourable Society will be pleafed to fee the method of preferving feeds in wax prove fo ་ ་ ་ ་ * Dr. Carol. Linnæus gives a particular description and figure of the Quaffi tree, which grows in the neighbourhood of Surinam in South America, and of the root having been administered at Surinam, with great fuccefs, in malignant, remitting, and intermitting fevers; and he tells us, that its virtues were first discovered by a flave of the name of Quaffi, from whom the tree got its namc. the copy of a letter on the good effects of this root, which I hope. will be acceptable to the Society, as it may excite phyficians to make trials of this medicine, which feems to promise to be of fo much use.. The original letter was given me, by the gentleman to whom it is addreffed, while I attended him laft year when he was here in England for the benefit of his health. I am, ' SIR, Your moft obedient Jermyn-Street, March 8, 1768. Copy of a letter from Mr. James Farley, Practitioner in Phyfic in the Ifland of Antigua, to his Partner, Mr. Arch. Glofter, in London; dated Antigua, July 26, 51767. SIR, mach; a dram of this root has ef- I have given it in fevers, joined Dr. Warner has fent Dr. Jackson a piece of it: he faw the good ef fects of this medicine, in a patient, captain B- -n, who fails for London to-day. He attended him with me. I could not get the bark to fit on his ftomach; for he had a D. MONRO. perpetual vomiting, and could not keep down any nourishment whatever. I prepared a decoction of a dram and a half of the Quaffi root, and a dram of the rad. ferpent. virgin. When it was ready, I fent for Dr. Warner, that he might fee the patient before I administered it: he complained of fome pain on touching the pit of his ftomach, had a very fluggish low pulfe, a great pain over his eyes and in his decoction, which furprizingly eye-balls, and vomitings. He took the pút a ftop to his vomiting he had no return after the firft dofe, and kept down every thing. We indeed gave him fome camphor and fal fuccini, on account of the Дuggifhnefs of the pulfe; but I have tried it alone in a decoction, with infinite advantage, R. Tr has been ex Mtremely I have lately tried it in three or four cafes where there has been a tendency to putrefaction, and the bark would not ftay on the fto Signed, J. FARLEY. [Received October 4, 1768. An Account of fome Experiments, by the |