Organic Chemistry.

Chemical meaning of the term "Organic Bodies." Proximate and Ultimate analysis illustrated by means of some common article, such as Flour.—Leading characters of the main groups into which Vegetable and Animal Products naturally divide themselves; such as Saccharoids, Fats, Alkaloids, Coloring Matters.—The Alcohol Group. The Fermentations.—Chief Constituents of Animal Food: Albumin, Fibrin, Casein, Gelatin.

To what has been said at page 11 of this Pamphlet respecting the growing use made in Chemistry of hard words, I may here add that it is equally desirable to avoid hard things. It is a hard thing when nearly everybody is agreed as to the meaning of the word Aeil, to be told that Acids are Salts, and that their leader, Sulphuric Acid, is a Hydric Sulphate, being a combination of Sulphuric Anhydride with Hydric Oxide, alias Water. So on with Carbonic Acid and the rest. Pedantry like this is but too apt to disgust would-be students, and it is obviously more profitable to grant to each anhydride the modicum of Water which renders its properties available, and gives life to its acidity. There page 47 are many Organic Acids, which in their ordinary condition contain a determinate proportion of Water of Crystallization without being called "Hydrates," any more than we would call "Hydrates," crystallized specimens of Salts.

One of my chief reasons for writing, about 1871, the Industrial Course above mentioned, was that I wished to show that a much fuller account of Chemistry than that squeezed into two Lectures in my "Science made Easy" Course, an account in fact that might suffice for most Working Men, might equally be given without troubling their minds with those equivalents and symbolic notations, which however convenient they may be to a Student acquainted with the chemicals referred to, are stumbling-blocks to a beginner ignorant of them. Their use was accordingly dispensed with, not only in the 8 Lectures on Inorganic Chemistry, but in 12 devoted to Organic Chemistry. Now the same care should be taken in the Chemistry of the first Period of a Bionomic Course for Schools, Equivalents and Symbols being-reserved for the second Period, of which indeed they will constitute one of the chief distinctions. Roscoe, than whom one could not cite a better authority, distinctly says the study of Combining Weights, Symbols and Notations should follow, instead of preceding a visual acquaintance with the bodies to which they apply (Sec Roscoe's Chemical Primer. Macmillan. 1872). Prof. Barff in the Preface to his "Introduction to Scientific Chemistry" says, "I have always found that beginners have great difficulty in conceiving abstract numbers, and that symbols and equations are regarded by many as almost insuperable impediments."

It is a pity that a principle supported on first-rate authority should hitherto have been very little carried into practice, the above Primer for children, by Roscoe, and Rigg's "Easy Introduction to Chemistry," being the only examples to the purpose, that have come page 48 under my notice. It would be a great convenience to teachers of Chemistry at high-class Schools, where that science, if taught in earnest, must almost necessarily be gone through twice, between the ages of 10 and 17, to use a manual purposely written in two parts, or stages, approximately corresponding to our two Periods, and carefully avoiding the various drawbacks to which attention has been directed. The first would give main outlines and fundamental principles without symbolic notations, the second would introduce these, and in going over the ground again, filling in and extending, would make good use of them for explaining what cannot well be made clear without them.—Almost the only plan now available seems to be to select some comprehensive Manual, and to indicate by conventional markings on a standard copy, the subject matter to be taken in the first Period, and repeated in the second, that to be taken in the second only, and perhaps certain portions that may be omitted altogether, or reserved for a third Period. The copies in the hands of the pupils must of course be marked conformably. Trouble might be saved by a work giving in bold type the matter to be studied in the first Period, and in different print that to be taken additionally in the second Period.—When educational series present first and second stages, i.e. Elementary and Advanced Books for each branch of knowledge, it is obviously desirable that the corresponding works be written by the same author, as was the case with the Botanical ones by Balfour in Collins' series.

Whilst I highly appreciate the educational value of Laboratory Practice, I feel bound to warn Teachers of Chemistry against allowing beginners too free a use of Chemicals. I speak from experience, having had Chemicals at my free disposal when I was about 12 years old, and a good Laboratory at 13. I had however learnt caution from what I had seen happen to a pharmaceutical friend, from whom I took private lessons at page 49 the time that I was following the course of Chemistry of the celebrated Professor Orfila at the Royal Athenaeum. Paris, in 1818. My friend was showing me the "Philosopher's Lamp," which unfortunately is one of the first experiments that a chemical student arrives at, and without proper apparatus, one of the most dangerous. The flame having become extinct, he took out the cork and tube, replacing them after he had added a little acid. After waiting what he imagined to be sufficient time, he held the point of the tube to a candle, when the bottle exploded in his hand, scattering fragments of glass and acid spurts all over the shop. We were quit for a fright, and this specimen of imprudence had a salutary effect on my mind, and I never had any mishap worth mentioning, though certain narrow escapes warrant me in earnestly recommending that tyros should be specially trained in forethought and caution, and enjoined not to attempt any dubious experiments without the presence of a practised operator.—I used at one time to find entertaining and instructive, the carrying out in the small way of industrial processes, such as the manufacture of scented Soap, Dyeing in various colors, Distillation of Essences, preparation of Cough Lozenges with Liquorice, Guimauve and Tolu; &c. But a better occupation for advanced students would be Food Analysis, of which Bionomy in dealing with Adulteration, Fraud and Impurities in general, suggests so many useful applications.