Substances Formed

SUBSTANCES FORMED.

Name. Formula. - Carbonic + Water. — Oxyacid. gen.

1. Vegetable Acids— Tartaric acid H. = .4- 6110 — 100 Malic acid 11. = 8CO2 6H0 — 120 11 Citric acid = 8H0 — 180 2. Carbo-hydrates Cellulose 0.211101e = t 10H0 — 240 Starch . 0 = 10H0 — 240 Cane-sugar = 12002 11110 — 240 & Other Neutral Rodies*— Mannite = — 14H0 — 200 Salicine = — 18H0 — 560 Pectine C2,1121024 = — 21H0 — 530 Hematoxyline = — 14/10 — 660 Elaterine ' 0,0112501ri = — 25H0 — 1270 4. Oxygenated Volatile Oils, and Allied Acids— Oil of bitter almonds 02 = — 1L10 — 320 Benzoic acid = — 6110 — 300 Oil of cinnamon. • = — 8110 — 420 Cinnamic acid C,,H, = — 8110 — 400 11. Oily and Fatty Acids— Acetic acid C4 H4 02 = 4110 — 800 Butyric acid H. = 8H0 — '200 Valerlanic acid C.0H = 10002 10H0 — 260 Stearin acid = 36H0 — 1040 & Resins and Camphors— Many resins C,0H, 0 = ' t 7H0 — 260 Camphor 0 = 8110 — 270 Borneo camphor = 20002 18H0 — 560 7. Carbo-hydrogens Oil of lemons C. H4 = — 4H0 — 140 Oil of turpentine . 1000, — 8110 — 280 Oil of juniper C16H12 = — 12110 — 420 Cumote 0181112 = 18CO2 — 12H0 — 480 Cymole = — 14110 — 540 A glance at the composition of these seven groups shows that they present a series of deoxidations, till in the sixth, very little oxygen, and in the last, no oxygen whatever is left. Thus, leaving out of view, for want of space, the Compounds in which nitrogen and sulphur enter, "oxalic acid is first formed, and then malic, tartaric, citric, etc., acids from it or from each other; then sugar, starch, etc., from the acids; bitter, acrid, and colored compounds from the sugar, starch. etc. ; then oxygenated volatile oils; and then acids perhaps also from sugar, etc. ; then the oily and fatty acids, either from the pre cedin.* oils and acids, or from sugar; then theresins from the fats, or from sugar; and lastly, the cerbo-bydrogens. Thus, we have a picture of the whole process of vegetation

5 1n this group, which is very numerous, compounds of a most discordant character appear. Of tha specimens we have selected, the first closely resembles a sugar; the second is a pure bitter; the third, a gelatinizing substance; the fourth, a pigment; zuid the fifth, an acrid poison.

as far as concerns compounds devoid of nitrogen and sulphur; And we find it uniformly to be one of deoxidation."—Gregory, op. cit., p. 548. To produce nitrogenous com pounds, such as asparagine, amygdaline, nicotine, .morphine, caffeine, etc., it is only additionally necessary that ammonia should be present, and the plant by a similar pro cess gives rise to nitrogenous products, the process being shown as below: Asparagine C8 = — 4H0 — 2NH, — 120 Amygdaline C40N H8 09 = 40008 -r 24H0 — NH, — 820 Nicotine C2oNoltli 200O5 — 8H0 — 2NH8 — 480 Morphine Cs4N = 34CO2 — 10110 — 800 Caffeine = 16C09 — — 280 It is easy to show how the sulphur contained in certain oils (oil of garlic, for example) is probably obtained by the reduction of the sulphuric acid existing in the sulphates of the soil; but the composition of the albuminates containing both sulphur and nitrogen is so complex that we cannot venture to attempt a popular explanation of the mode of formation of these matters from the simple food of plants. On this subject the reader may consult Liebig's Agricultural Chemistry, Letters on Chemistry, and Laws of Husbandry; 3Ittlder's various works (a new edition of his great work is now being translated, in parts, into German); Rochleder's Phytochemie, and the portion of Gregory's Organic Chemistry, and of the third volume of Gorup-Besanez's ilandbuch der Chemie, devoted to this question.