which lie between the least refrangible blue, and the extreme limits of the violet rays of the visible prismatic spectrum-the maximum darkening effect being produced by the mean blue ray, whilst the bleaching effect appears to be produced with the greatest energy by the least refrangible violet rays. NEWLY DISCOVERED MINE OF MANGANESE, NEAR GIESSEN. We have been informed that manganese of very superior quality has recently been discovered in the neighbourhood of Giessen. An assay made by M. Barruel has been forwarded to us, which very satisfactorily proves its superiority. Professor Liebig always uses it in his laboratory, and speaks very highly of it. It has also been analysed by Dr. Ettling. We expect to receive a sample of it very shortly, and will immediately perform and publish an assay of it, in order that our readers may be enabled to judge of it for themselves, and to avail themselves of the advantages which it offers. We understand that it can be very economically imported to England. IMPROVED ARRANGEMENT OF BLOWPIPE AND LAMP. MR. GLASS has exhibited to us his improved blowpipe and lamp. It is extremely well adapted for the ordinary glass-blowing operations of the laboratory. Mr. G. is an exceedingly skilful operator with this instrument, and informs us that he finds it invaluable for the preparation of all glass tube apparatus. He prepared some test tubes in our presence by means of it. The blowpipe is fixed at the required distance and height from the flame by means of two screws, one on the top of the lamp and the other at the back of the blowpipe, as will be shown by the cuts, by the adjustment of which, and the depression or elevation of the wick, flames, as in Figures 1 and 2, may be produced by the action of the mouth alone, both the hands of the experimenter being left entirely unencumbered and at perfect liberty for the manufacture of glass tube apparatus and all other blowpipe experiments. One hundred grains of pure silver supported on charcoal may be fused with facility by the pointed flame. The wick-holder of the lamp is a decided improvement, for the wick is large, having a surface of one inch and a half by an inchis not compressed-and always resting on the bottom of the lamp allows the capillary action of the fibres of the cotton to take place with freedom, thus keeping it amply supplied with oil, and preventing it from crusting. When raised to allow a large flame, it is used without the blowpipe for bending tubes. The whole is a very simple and effective piece of apparatus, cheap, easily manageable, not liable to become deranged, and always ready for use-points of much importance to the practical chemist. Mr. Glass recommends for its use the best sperm oil. Fig. 3 gives a section of the brass nozzle of the blowpipe, full size, every one of which is carefully examined and tried by Mr. G. before it is fitted to the mouth-piece. FIG. I. ! and it is only by checking this tendency, by the substitution of a yellow for a blue light, that the plant can be brought into its flowering and seeding state. The etiolating influence of the green rays was observed upon, as well as the power which plants possess of sending out shoots of a great length in search of that light which is essential to their vigor. THE peculiar influence exerted on the germination of seeds and the growth of the young plants by colored light, has been for some years the subject of the author's investigations. The results show the surprising powers exerted by the more luminous rays in preventing germination, and in destroying the healthful vigor of the young plant. Plants, when made to grow under the influ- SECOND MEMOIR ON MANURES.* ence of the red rays, bend from the light as something to be avoided; while the blue or chemical rays are efficacious in quickening the growth of plants. Since the publication of the last Report, the author has tried plants of a great variety of kinds, and the same effects have been produced. It has, however, been found, that although blue light accelerates germination, and gives a healthful vigor to the young plant, its stimulating influences are too great to ensure a perfect growth. The strength of the plant appears to be expended in the production of a beautiful deep green foliage; BY MM. BOUSSINGAULT AND PAYEN. tablish the comparative value of manures by the results of analyses. The practical observations which have since been communicated to us seem to justify the principles which we laid down as the basis of this estimation; at least, no serious objection has been raised, and the kindness with which enlightened practical men have received our former IN our first memoir we endeavored to es * Annales de Chimie et de Physique, Vol. VI., 1842. labors has induced us to complete our work | certain plants, as plaster for leguminous by examining all the manures which it was possible to obtain. For the more easy comprehension of the observations given in this second memoir, it will be sufficient for us to repeat the definition which we gave of powerful manures: now, as then, this definition appears to be the correct expression of well-proved facts. "Manures are of so much the greater value as the proportion of nitrogenous substance is stonger and predominates in it, especially relative to that of the non-nitrogenous organic matters; that, finally, the decomposition of quaternary substances is gradually operated, and follows better the progress of vegetation."* We intend here to define the value of manures applicable to cultivated lands, which contain the residue of previous crops-vegetable remains, poor in nitrogenous matter, but rich in ternary organic substances. It must, besides, be admitted with us, that intelligent agriculturists will be able to procure, with profit, and at low price, the mineral matters which may sustain the normal composition of the soil, and thus ensure the influence of manures. In order that the manure spread on the soil might alone subvene to vegetable nutrition, it would be necessary for it to contain all the organic and inorganic elements which, without being derived from the atmosphere, would be, in the end, assimilated during the life of the plant, and contained in the crop. In this case, the manures should also vary according to the nature of the land, the climate, the season, the kind of vegetable cultivated, the exposure and inclination of the ground, and, finally, according to the influence of the subsoil and the residues of previous crops. If this hypothesis were admitted, the composition of manures ought to be so complex and variable that a general rule would be impossible; scientific data would be vain, for the required conditions could not economically be combined: it is therefore, convenient to divide, as has long been done, into two classes, the matters used for fertilising land: inorganic compounds, independently of the chemical properties which they communicate to soils by furnishing them with the mineral substances indispensable to the complete development of vegetables, evidently contribute to the improvement of the physical qualities of the soils in culture. Such are the salts peculiarly suitable for *It is therefore the nitrogen in combination in the substance that is especially useful, and its proportion that indicates the richness of the manure, plants, those which occur in the greatest number of vegetables, substances with an alkaline reaction, as lime, potassa or soda leys, wood ashes, &c., which in general favor vegetation on all soils. These matters, so useful to agriculturists, are comprised under the denominations of improvers and stimulants. We may regard, either as stimulants, or as manures, the substances by aid of whichwe are enabled to furnish to plants the water indispensable for their more productive development: organic remains macerated in pools, irrigations themselves, too frequently neglected where they are possible, serve to attain this important object. Manures, properly so called, are of organic nature; they should supply, on the lands, the deficiency of gasefiable or soluble aliments, so that the vegetables may assimilate them. Now, among these aliments, those were formerly erroneously considered the most desirable which could give rise to the most abundant production of carbonic acid. It was wrong, we repeat, for these are especially superabundant in continually cultivated lands, whilst putrescible nitrogenous matters, undergoing the most rapid decay, should, consequently, be most frequently added to the soil: it is always necessary to renew the provision of them, which is continually exhausted. They may then properly be pointed out to agriculturists as most worthy of attention, and if their proportions in the present manures be determined, useful information will be given, and the best means of detecting the frauds prejudicial to agriculturists relative to commercial manures will be given.* It is now, moreover, a question judged by numerous concordant facts, and generally admitted by our most distinguished agricul tural writers. They also know that certain manures *The numerous disputes between agriculturists and merchants, relative to the disinfected manures and the black of refineries, have shown how illusory were the old processes of testing their value: the estimation of the nitrogen is very advantageously substituted for them: it is adopted by M. Malaguti, one of the learned profes sors of the Faculty of Rennes, not far from the localities which have derived such profit, in agriculture, from an extensive application of these manures. Thus commences the realisation of a wish expressed by M. de Michel, and taken into consideration at the last meeting of the General Council of Agriculture. furnish at once amendments, stimulants, water, and more or less nitrogenous organic aliments such are most dungs, which, on account of the multiple functions they fulfil, should be appropriated to the soil and to special cultures: fresh for dry and sandy lands; hot for argilaceous, humid, and cold soils. As regards rich manures, transportable to greater distances, they may be beneficially applied to all lands, for all cultures, provided that this action be favored, and that the power of the soil be developed by amendments, and irrigations obtained on the spot or not far from it. In order better to fix the ideas on this subject, we quote an example which we have mentioned elsewhere: on a dry, sandy soil, to which dung thoroughly impregnated with water was perfectly adapted, it was attempted to replace this manure by dry blood, of equal value; the result is easily foreseen: the crop failed. Should it be concluded from this that a manure rich in powerfully nitrogenous matter is useless or injurious on a light soil? No. without doubt; for such a manure, mixed in small proportion with fresh dung, so as to contain, in the total, the same equivalent of nitrogen, rendered the vegetation finer and the crop more abundant than in the ordinary culture, in which fresh dung alone was employed. It is thus that green manures, or simple irrigations, ensure the efficacy of hot dungs on sandy and dry lands.* The nature and value of the indications which may be drawn from our analysis being thus well defined, we will add some particular observations on the matter comprised in this new work. the superficial layers of the soil by the de- to The power of leaves as a manure is proved in Alsatia in all the Communes near forests; in such localities the cattle receive no other litter, and the latter, as analysis shows, is already a manure of a high value. Madia sativa.-This plant seems suited to the economical preparation of a green manure; such, at least, was the idea of M. Bazin (of Meuil-Saint-Firmin, Oise), and the first results obtained will encourage new experiments. In two months, in the favorable season, a land of good quality is covered with flowers. This was the period of manuring; it was at this time that M. Bazin sent us an average sample of the plants, roots, stems, leaves, and flowers. The whole, submitted to analysis, gave a strength rather exceeding that of farm-yard dung.* The weight of the crop, estimated by M. Bazin at 1,250 kilogrammes per hectare, would be easily obtained, according to this agriculturist, in tolerable lands, if the year, being more wet, were more favorable than 1842 to the development of herbaceous plants. Branches and Leaves of Box.-We analysed box with its young shoots, its stalks, and its persistent leaves, as it is cut in the South, according to the indication transmitted to us by M. de Gasparin; this manure may also be very simply prepared, by leaving it in the streets, exposed to grinding, by the feet of horses and the wheels of vehicles. It will be seen by the numbers given in the table, that the proportion of nitrogen causes it to greatly resemble the leaves of beech. Grounds of Cyder-Apples.-With several agricultural writers it still remains a question whether the grounds of apples may be considered as true manure, or, on the contrary, more injurious than useful: both opinions are founded on positive facts. In lands containing very little carbonate of lime, these residues have generally produced a bad effect, and, in other soils, disadvantageous results have always been observed when the grounds of apples have been found alone, or mixed with very little earth, too near the roots of plants. This unfavorable * When this green manure is dried, its richness is 2 that of madia, analysed after the production of the seeds. 3 I influence appears to be owing to the acid reaction of the soluble part of these residues; and, indeed, if they be saturated with a sufficient quantity of ley to communicate to them a perceptible acid reaction, the apparent anomalies cease, and the useful effects of the manure becomes proportionate to the quantity of nitrogenous matter which it contains; the liquid with which it is impregnated, and which it very tenaciously retains, gives it the character of a fresh manure, more particularly applicable to sandy lands. In Alsatia, one of us manured for a long time, and with success, artichokes with the grounds of apples, associated with the grounds of grapes, in a very argillaceous and sufficiently calcareous soil. In most cases, the grounds, like all acid products, are correctly placed among manures, their acid principle being adapted for retaining the ammoniacal vapor. Grounds of Hops.-This residue of breweries, which was formerly rejected everywhere, is now in use in many localities; it is calculated for dividing compact earths: it may be much improved by drying in the air, then mixing it with the litter of cattle; it then serves as an excipient for urine, and the increase of the proportion of nitrogenous matters is so much the more advantageous, as it reduces the proportion and influence of of the non-nitrogenous part of the organic matter. This increase of nitrogen may be calculated by taking account of the strength of urine in this respect. Scums of the Defecations of the Juice of Beet-root. These scums, obtained in sugar manufactories, are formed of albuminoïd substances, coagulated under the influence of temperature, and of an excess of lime: they have an evident alkaline reaction; the organic matter which they contain is more abundant in nitrogen than that of dung; in their re-action and chemical composition, they unite qualities favorable to plants; practical observations show that their useful effect answers to these theoretical indications in the normal state, pressed, but still quite moist, 7465 kilogrammes represent 10000 kilogrammes of farm-yard dung. The scums, on leaving the presses, have a plastic consistence, which is opposed to their being spread uniformly on land; to avoid this inconvenience it is necessary to allow the scums to dry until their mass becomes friable; they are then easily crushed under a vertical mill, and they are easily employed like other pulverulent manures. In the scason in which beet root sugar is generally manufactured (from the end of September to January), the desiccations would be slow and expensive; it is more conomical to dilute the scum with sufficient water to obtain a thin pappy mass, which is easily mixed with dung, unless it be preferred to spread this matter with a scoop, like Flemish manure. Slices of Beet Root treated by Maceration. This residue, almost entirely exhausted of sugar by the process called maceration, is poorer in nitrogenous substance than the pulp leaving the presses, and it contains a much more considerable proportion of water; its strength as a manure would be only 0.022 of that of farm-yard dung. Its equivalent, represented by 4136, dung being 100, shows that it would be necessary to employ about 40 times as much for an equal surface of land. The practical experiments on a large scale, agree with the results of analysis; it is therefore necessary to reduce this residue to a smaller bulk, by expelling a portion of the water by a special pressure; even then it constitutes a weak manure, which, in general, the expenses of carriage render of little use. Cakes.-Among those which we have analysed since the publication of our first memoir, it will be seen that the richest arise from the seeds of camelina, poppies, and nuts, which are nearly of equal quality; then come the cakes of hemp, of seeds of cotton, and of beech. The latter, which is very ligmous, is sometimes employed as fuel; the oily produce of beech is, moreover, very variable. The extraction and purification of the oil of cotton seeds, constitute, in France, a new manufacture, which will leave a residue useful to our agriculture: its value, as a manure, would be about ten times that of normal dung, as the strength of these two manures indicates. Dung of the Inns of the South.-We analysed it with M. De Gasparin, to whom we owe all the information concerning its applications; this manure arises from the excrements and litters of horses and mules, fed with hay and oats. A sample was taken after it had been heaped up for a month, still warm, but sufficiently moist not to turn white; the straw which it contained was softened and crushed, but without sensible decomposition; it weighed, in this state, 660 kilogrammes the cubic metre, and 820 kilogrammes if strongly pressed; it contained 0:3942 of dry matter; this represents 0.725 if its weight of organic substance: the ordinary and fixed price of this manure is 1 fr. 30 cent. the hundred kilogrammes; this quantity gives to a culti vator an increase of product, estimated at from 2 to 5 francs, in watered lands, and only from 93 cent. to 1 fr. in dry sandy soils. This fact, which is highly worthy of atten |