Laftly, that the lofs of weight is in the inverle ratio of the quantity obtained. The object of this memoir is merely a comparison of the quantities of glutinous matter furnished by the different kinds of wheat; it is confequently indifferent in what ftate they are estimated, and alfo what proportion they bare to the weight of the flour. It is fufficient for me to have fhown, that the four of twenty different forts of wheat, after being treated in the fame manner, furnished a quantity of vegeto-animal matter which, whether it was weighed immediately after this extraction, or not until it was completely dried, was in different proportions. very This comparative trial having informed me of a circumftance Ï wifhed to know I proceeded to the inveftigation of another. It appeared to me important to determine, whether manures of any kind could contribute to the information of the glutinous part, and if fo, what thofe manures were. With this view, in the fpring of the year 1792, I prepared, in a piece of land, the foil of which appeared to me all of the fame nature, nine beds, each containing two perches, of twenty-two fquare feet; they were exactly fimi lar in every refpect, excepting in the manure made ufe of to them. In one of thefe beds, I folded a flock of theep and goats, amounting in the whole to one hundred and forty; they remained on the bed about two hours; and the refult of the folding appeared to me to be fuch as commonly takes place from that operation in the departments of Seine-et-Oife, Seine-et-Marne, Loire, and Eure-et-Loir, Another bed was manured with two facks of horse-dung, in a rather rotten fiate. The third, with two facks of cowdung, in the fame ftate. The fourth, with fixty-four quarts of human urine. The fifth, with thirty fix quarts of bullock's blood. The fixth, with the remains of plants, reduced into the ftate of mould. The feventh, with three bufhels of pigeon's dung. The eighth, with human excrement in powder, prepared at Montfaucon. The ninth was not manured at all. I fowed every one of thefe beds with the fame kind of wheat; namely, that kind which has fimooth white ears, without beards, the grain of the ufual colour, the firaw eighth part. This affertion is not exaggerated; for, after having collected the glutinous part of different kinds of wheat, and deprived them as much as poffible of their starch, and of their water, and dried them thoroughly, I found, at the end of four years, a decreafe of weight, amounting to two-thirds, to three-fourths, to four-fifths, and even to feven-eights, according to the fpecies or variety of wheat made ufe of; and I very feldom obtained more than two ounces, in a ftate of drynefs, from a pound of wheat. It must be obferved, however, that the weight of the glutinous part cannot be compared with that of flour in its ufual flate; becaufe a pound of flour, which did not appear to he wet, being put to dry gradually upon a warm ftove, was, in the space of four-and-twenty hours, reduced to fourteen ounces; that is to fay, it loft one-eighth part, without appearing burnt, or fuffering any alteration in its colour. From which it follows, that, in order to estimate truly the lofs of weight in the glutinous part of a pound of flour, it must be extracted from a pound of flour, which has already been dried, or elfe be con→ fidered as the produce of only fourteen ounces of flour. hollow, hollow, and which is ufually fown in the month of March. Although a comparison of the quantity of grain produced was not the principal object I had in view, yet I think it right to obferve, that the bed manured with pigeon's dung was that which produced the greateft quantity of grain. After that, I gathered the greatest quantity from the two beds manured with human excrement, and with human urine. Next to thefe, the greatest quantity was produced from thofe manured with bullock's blood, and with horfedung. The beds manured with the remains of plants, and with cowdung, were lefs productive. That which had no manure at all, produced little more than double the quantity which was fown; whereas the others produced more than fix times the quantity fown. With refpect to the quantity of glutinous matter, which was the principal object in view, the refult of the experiment was as follows: The wheat of the bed watered with urine, produced fix ounces of glutinous part from a pound of flour, not dried. That of the bed in which the sheep and goats were folded, and that of thofe manured with horse-dung, with cow-dung, with pigeon's dung, with bullock's blood, with the remains of plants, alfo that to which no manure was used, gave five ounces of glutinous part per pound. Lastly, that which was manured with human excrement, gave only four ounces per pound. It will, undoubtedly, be difficult to conceive, why the eight manured beds above-mentioned did not give an equal proportion of vegeto-animal matter; for the wheat was all produced from the fame feed, was fown in land which was the fame 10 in appearance, and the manure was applied in the ufual manner, It is evident that the manure was not the cause of this difference; because from the wheat which grew in the bed not manured, I proeured five ounces of glutinous matter per pound; that is, a quantity equal to that procured from the wheat of fix other beds manured in various ways; a cir cumftance which naturally leads us to feek elfewhere for the cause of the variation in the proportion of glutinous matter. I fhall here observe, that the wheat made ufe of for the above experiments in fpring, was the fame as one of thofe on which I made the first-mentioned experiments in the autumn of 1791; and that, in the experiments of 1791, it produced only three ounces of glutinous matter per pound, inftead of five or fix. This would lead us to fuppofe, that wheat fown in March contains more glutinous matter than that fown in autumn; or at least that the latter, notwithftanding its longer vegetation, does not contain a greater proportion of it. As a brief recapitulation of the preceding results, I shall state, that different fpecies and varieties of wheat produce various proportions of the glutinous part, which is more or lefs brittle, and which, before it is dried, fometimes amounts to more than a third part of the flour; but, when dried, does not commonly exceed one-eighth. Manures do not appear to contribute to the forma tion of this fingular substance. Many interesting circumftances. refpecting this fubfiance ftill remain unknown; for, it may reasonably be inquired, firft, whether it is proved that no other grain contains this this glutinous part. It has, without doubt, been afcertained, that it cannot be obtained from rye, from barley, or from oats; but, have experiments been made upon the flour produced from the feeds of other kinds of graffes? Is it not probable, for inftance, that it would be found in the grain of what is called mannagrafs, fo much ufed in Poland ? Secondly. Rural economy would require that we fhould examine, whether the wheats of one diftrict always contain more glutinous part than thofe of another; this examination would neceffarily take feveral years. up * Thirdly. We fhould alfo determine whether the expofition of the land, and the nature of the foil, ought to be admitted among the caufes which contribute to the formation of the glutinous part. For this purpofe, it appears neceflary that we should form an artificial foil, of which the ingredients were well known; a difficult talk, and one which can only be undertaken by a zealous perfon, who refides in the country. Fourthly. Suppofing that thefe inquiries thould produce merely negative proofs, and that only a concurrent or fecondary caufe fhould be difcovered, it will then remain to be known, why, of the various grains which ferve us for nourishment, wheat is the only one that appears to contain this vegeto-animal matter, or at least that contains fo much of it. We must not be too fanguine in expecting to difcover this laft truth; because it may depend upon the particular organization of the vegetable, which organization we cannot inveftigate. But, it will be a great deal to have difcovered in what confifts, or upon what depends, in the various fpecies or varieties of wheat, the greater or lefs quantity of this glutinous matter, which is of fo much confequence in the process of making bread. Experiments made with a View to afcertain the Truth and Importance of Dr. Hunter's Opinions refpecting the Food of Plants, by Major Thomas Velley; from the Letters and Papers of the Bath and Weft of England Society for the Fucou ragement of Agriculture, &c. THE laudable exertions of the Board of Agriculture having called forth various expedients, both from the practical and theoretical improvers of land, for the advancement of cultivation in general, I elected, from among fundry tracts recommended by the board, the one intituled, "The Outlines of Agriculture," published by Dr. Hunter, the learned editor of Evelyn's Sylva; in which work the above-mentioned tract made its first appearance, in the form of a note. In the feventh page of the pamphlet, the ingenious author thus ex * M. Parmentier, in the work already quoted fys, that there are fone kinds of wheat, particularly those which grow in wet places, or in poor foils, whofe product of glutinous matter fcarcely amounts to one ounce per pound; and that, on the contrary, there are others which contain near two ounces. I shall not contradict this affertion, for the fact is certain; 1 thall only obferve, that if by poor foils M. Parmentier means dry and stony ones, it appears to me more natural to suppose, that as the wheat which grows in fuch foils is of good quality, it fhould contain a greater quantity of glutinous part. This, however, requires to be more carefully examined. preffes a Pleafed with the information, I determined to give the fairest trial to the experiment, and chofe piece of ground which was frefh, and had not received any manure: in this I made fix contiguous beds. I then marked out, in each bed, 128 fpots, four inches afunder every way. In the firft bed planted the fame number of barley feeds, which had been fleeped three days in the above mixture. After this, I planted, in the fame manner, and in the adjoining bed, the fame quantity of feeds, dry, and not fteeped; but, before the foil was clofed upon them, I poured into every hole two-thirds of a drachm of the faid compofition; a quantity fo finall as fcarcely to fill a tea-ipoon, and which could not have been fuppofed to produce any visible effect. I then planted, in the third bed, the fame number of feeds in their natural fiate, unprepared, and without any compofition. The following obfervations I mede with great accuracy. The feeds which had been steeped did not make their appearance fo foon, by eight or nine days, as the grain which had been planted with 12. I repeated the fame experiment with oats, in the fame manner as before ftated, in every refpect, and planted them in the three adjoining beds; and it was fingular enough to obferve the fame effects precifely, as to the time of their coming up, and of their ripening, as well as with regard to their produce, which I had before remarked in the barley. In both inflances, the unprepared grain was much more forward in its appearance and ftate of maturity, as alfo much more abundant, than either of the other two. All the feeds were planted with the Norfolk dibble, exactly at the fame depth, at the fame time, and in adjoining beds, under the fame afpect, in an open though rather loomy foil, which had not been manured. yet, as the effects produced by the compofition, and by the varied modes of applying it, were remarkably fimilar in the different forts of grain, planted at the fame time, and in the fame foil, I think fuch an ob jection cannot reafonably invalidate an experiment of this nature; more efpecially when it is confidered, that a greater degree of accuracy and precision can accompany fimilar attempts upon a fmaller fcale, than, when extended to a greater fcope; and, if I am not greatly mistaken, fome of the very ingenious obfervations which the learned chymift, Dr. Ingenhoufz has lately given to the world, with respect to the nutriment and fupport of vegetable life, have been found upon experiments even more confined in their extent, though not lefs worthy of attention on that account, than thofe above cited. ANTIQUITIES. |