parent first with manganese, while we are unable, in a large proportion of our different kinds of soil, to demonstrate, except with great difficulty, the existence of manganese, it can be shown in the ashes of plants with the greatest facility, and while generally very peculiar means are required to demonstrate the other metals except iron, in the soil, the existence of copper, lead, tin, &c., in the ashes of plants, can be evidenced by very simple chemical operations. Here, then, a concentration, a collection of these rarer matters has accrued, caused, doubtless by the solubility of their ores in water charged with carbonic acid. Let us consider, now, the peculiar mode in which manganese occurs in sea-weeds: It is in combinations soluble in water, probably with organic acids. As the manganese becomes insoluble in water upon burning the plant and it is not at all unreasonable to suppose a similar condition of the other metals, it follows again that they would be exposed, upon the rotting of the plants, to be washed away, and the soil would thus lose more rapidly these, according to all probability, highly necessary constituents of a luxuriant vegetation. A consequence of these relations is that the soil must lose these materials by means of active cultivation, and our manures are not able to replace them in a sufficiently large quantity. It lies in the nature of the matter that the propositions here laid down must be uncertain as yet. The matter is too new, and our observations have been in this regard too limited to cause us to stop, satisfied with our investigations, but we should strive for a far more extended experience before we consider the matter established and decided; and the object of this communication is especially to direct the attention to these substances, which have not hitherto been considered as plant-nourishing. If only a small part of what I have here expressed, as based upon my own and other chemists' experiments, be confirmed by future experiments and observations, an actual progress in our theoretic sciences of the nourishment of plants will have been made, as well as in our practical knowledge of the means of calling forth a strong vegetation. I will now close this series of remarks with a definite proposition. It is well known that a much-used, and according to my experience, very useful means of preventing smut in wheat, is to soak the seed in a weak solution of blue vitriol, (sulphate of copper). If the remarks I have before made are not without foundation, then the copper serve to supply the young plants with this productive materials for nourishment, and thereby protects it from the attacks of those lower organisms. My proposition is that the same experiment be made with the potato; that when planting they shall be carefully soaked or moistened with a very weak solution of blue vitriol. It must not be forgotten that copper is a very poisonous substance, and too much of it would kill the young sprouts. I intend to dry out or wilt some potatoes, and then soak them out in a solution of one part blue vitriol and a thousand parts of water. CHEMICAL PHYSIOLOGICAL CHARACTERISTICS OF THE VARIOUS FORAGE PLANTS. The following pages are devoted to an examination of the various forage plants, and, without further preface, we commence with one of the most important, namely, the varieties of clover. CLOVER. The principal varieties of clover and their organic composition, according to the analysis of the same will be found complete in the following table: From Cirencester, beginning of bloom.. 66 London in full 66 Way. **The actual This column includes starch, sugar, dextrine, pectrine, gum, fat, wax and extractive matter. proportion of the nutritive substances is not given herein, because it can be calculated only, if the fat is also taken into consideration. *** From this it appears that the English hay is more nutritious than hay grown elsewhere. 76.6 4.3 11.4 5.8 1.8 1.7 Way states the average amount of fat-forming substances found in 14 analyses of different varieties, at 0.75 per cent., in green clover, and at 3.18 per cent. in clover hay. The results obtained by Eichhorn, Stockhardt and Boussin gault nearly corroborate this statement. The latter found the average of fat-forming material in green clover to be 0.9 per cent.; in clover hay, 3.2 per cent. This amount of fat-forming substances is worthy of serious consideration in experiments in feeding. The most essential points connected with the above analyses are as follows: 1. The great value of clover, as a nutrient in general, founded on its digestibility and richness in protein. The latter makes it a forage richer in protein than grain, which possesses only half as much protein in one part of non-nitrogenous nutritive matter. But grain is a more concentrated food than clover, because, in quantities of equal weight, it contains more assimilable nutritive substances, i. e., a very small amount of such substances as have no nutritive value, and are only a nutritive ballast. Since the amount of nutritive matter found in clover by analyses does not meet the theoretical expectations, in its nutritive effects, as far as observed, this failure was formerly ascribed to the woody fibre in the clover, in so far as it, by incrustating the nutritive substances contained in the cells of the plant, makes them less digestible and thus partly inefficient. This view, first advanced by Wolff, and then amplified to the extreme by the assertion that the nutritive substances in a fodder become the less available the more woody fibre is contained therein, was not endorsed by some vegetable physiologists who suggested another explanation. The latter is now confirmed; the incrustation by the woody fibre does not cause the slight effect of clover, for it has been shown that one-half of the woody fibre is digestible; but it is occasioned by those soluble substances shown by analyses to have no nutritive value at all, because they are organic combinations, bearing no similarity to the nutritive character of the pure protein matter, or to that of sugar and starch. Different amounts of such, unknown extractive substances are contained in the forage plants, and,. according to my investigations of this subject, stand in no proportion to the amount of the woody fibre. In explanation of this an analysis of a sample of Lucerne-esparzette hay is here given, in which the strictly nutritive portion is separated from the dissolved indifferent substances destitute of nitrogen. Water...... Protein substances.. Fat......... PER ONE HUNDRED OF HAY. Saccharine substances, reduced to starch.. 16:2 117 2.T 18.5 " |