where by so doing you can kill an isolated germ of disease instead of suffering that germ to linger and fructify while you are attempting a cure, for the precarious prospect of an insignificant saving, is justified by reason; it is also directly justified by experience, which shows that while the plague, propagated from a single germ, speedily becomes unmanageable, spreads from herd to herd, from province to province, and from country to country, multiplies in a continually increasing ratio, and exhausts itself only after ruinous havoc and a long course of time, it may be effectually eradicated by prompt and unsparing measures. The experience of Prussia is especially valuable in this respect. The plague has often appeared, says Professor Gerlach, in the provinces bordering on the Russian empire, in East Prussia, Posen, and Silesia, but it has never since 1815 penetrated eastwards, even so far as Brandenburg. Lastly, we must add, it has not been found to give way before cold weather or rain. The reverse seems to be the case. It is worse, Professor Gerlach informs us, 'in cold and wet weather, and better in warm and dry weather.' It spreads,' says Mr. Ernes, 'as fast in a cold as in a hot season.' The murrain of 1745 broke out here in early spring, the temperature of the preceding year having been low; and it is stated to have raged most violently during the winters, and to have diminished in intensity with the advance of summer. "These conclusions, which are all that for our present purpose it is necessary to state, are far, of course, from exhausting all that is known upon the subject. Beyond what is known, however, there is a large field of inquiry which may be usefully explored. To observe carefully the premonitory and progressive symptoms of the disease under various conditions-to determine precisely the period of incubation, the effect of remedial and of preventive agencies (including under the latter head disinfectants, therapeutical measures, and inoculation)-to ascertain within what range and under what modifications the poison may be communicated from a diseased cow to other animals of the same or different species-these are branches of investigation practically important, but which will take time. With a view to the thorough examination of them, we have obtained the assistance of men eminent in various departments of science, and we hope to be able to report on them hereafter. But we have now to deal with more pressing questions. Are the measures hitherto adopted to stifle the plague at home and stop its entrance from abroad effectual for the purpose? If not, what other measures are likely to be effectual? To these questions, having early satisfied ourselves of the general character of the disease, we at once directed our attention; and the evidence which we have received has been chiefly taken with a view to them." III. ON THE RECURRENCE OF SPECIES IN By A. C. RAMSAY, F.R.S. THE paper by Mr. Jenkins in the last number of this Journal, "On Strata Identified by Organic Remains" (an article which I have read with interest, and the value of which I appreciate), induces me to publish this brief communication with a view to point out that it seems to me that some of Mr. Jenkins' arguments may lead to a total misunderstanding of the reasoning employed in my anniversary addresses to the Geological Society in 1863 and 1864. My chief object in these addresses was to show the connection between unconformity and the partial or complete change of marine faunas during times unrepresented by strata, and in discussing the question whether (as had been asserted) a Silurian, a Devonian, and a Carboniferous fauna might all coexist in different areas, I stated if it were so, "that in the piles of formations" of Europe and America, "the chances are overwhelmingly strong, that in each or in some one area there might be a recurrent fauna, which is not the case." Mr. Jenkins quotes the foregoing passage, and a little lower in the page he points out that I refute myself in my own address, because in discussing the Lower Oolites, I state, that "the majority of the forms that passed upwards from the Inferior Oolite limestone seem to have fled the muddy bottom of the Fuller's-earth sea, and to have returned to the same area, when the later period of the Great Oolite began." "Here," says Mr. Jenkins, "Professor Ramsay acknowledges a recurrent fauna." Certainly there is a recurrence of forms, but only to a very limited extent. The fauna of a province or of a formation means the collective species of the province or formation, and not a small percentage of them. My arguments in part are based on facts of that kind, viz. that in certain cases there is recurrence of species not in mass but in small numbers. In this case, out of about 700 Great Oolite species, only about eighteen or twenty per cent. are found in the inferior Oolites beneath, whereas, from want of showing how I considered the question as a whole, Mr. Jenkins' readers might imagine that the fauna of the Great Oolite, is the fauna of the Inferior Oolite recurrent. This is very far from being the case, and in my address I do not hint at anything that would lead to an inference so erroneous. But supposing that there were a recurrence of Inferior Oolite complete species in the Great Oolite, or on a great scale, it may then occur to those who remember my addresses that they are expected to draw the inference, that the Inferior Oolite, Fuller's VOL. III. D earth, and Great Oolite are formations comparable in importance, physically and in their faunas, to the Silurian, Devonian, and Carboniferous formations, the faunas of which were supposed by Professor Huxley to have been possibly contemporaneous in different parts of the world. It might be allowable to compare the Oolitic Subdivisions named above, with any three minor subdivisions, for example, in Upper Silurian strata, but few Geologists will require to be reminded that such minor subdivisions are not comparable to the three great series, Silurian, Devonian, and Carboniferous, each of which contains several groups of formations, some of which groups are comparable to the whole Oolite series of Britain taken together. IV. SYNTHETICAL CHEMISTRY. 1 On the Synthesis of Organic Bodies. Lecture at the Royal Institution of Great Britain, February 12, 1864. By J. A. Wanklyn. 2. On Recent Chemical Researches in the Royal Institution. Lecture at the same Institution, June 3, 1864. By Edward Frankland, F.R.S. 3. On Researches in Organic Chemistry in the Royal Institution. Lecture at the same Institution, June 9, 1865. Same Author. 4. On Animal Chemistry. A Course of Six Lectures at the College of Physicians. By William Odling, M.B., F.R.S. Especially Lecture 5, reported in the 'Clinical News' of September 8 and September 15, 1865. THERE are hundreds of restless, prying men, who would to-day, as did the fabled Titan, steal down the fire from heaven and vivify a human form, or failing that, would be content to animate the merest speck of organized material. This is the aim to which the efforts of mankind, at least of our most earnest investigators, are half-consciously tending at the present time; but whether or not it will ever come within the scope of man's ability so to mould the elements and imitate the work of nature, as to fit them for the reception of that mysterious force or combination of forces termed "life," it is impossible to say; at least, it is not the will of Him who is the author of all force, that man should, at this stage of his existence, stand forth as a creator even of the humblest living form. To go a step beyond this, and affirm that there is this or that in nature which he cannot do, or should not attempt; to dogmatize upon the things of which he ought to remain ignorant, or whose investigation should be avoided as an impious attempt to pry into and interfere with the Creator's works, is to exhibit the greatest want of faith, not alone in man's powers and destiny, but in the might and goodwill of his Maker: it means, in fact, to abdicate man's noblest powers, neglect his highest faculties, return to the darker stages of his existence,-for where there is no progress there must be retrogression,-and to make him the image of God in name alone and not in nature. The story of Prometheus is, in common with many others of a similar character, merely a childlike fancy of man in the earliest stage of his history, which is every day approaching realization in another form, just as the efforts of the old philosophers and alchemists were the result of dreams which have become in our day living realities. The creative powers of man have to be educated, just as all his other faculties; and this, the highest portion of his nature, has been more gradually yet more systematically developed than any other. The principle upon which his mind has been trained may be exhibited by a very simple illustration. There are few of our readers who have not seen those interesting little puzzles shaped like a double cross. When the curiouslyformed pieces of wood which constitute this cross are placed in our hands for the first time and we are invited to construct the object, we often spend hours in the vain attempt to do so; but let the pieces once be put together by hands that are in the secret, and the cross presented to us entire, and give us then the opportunity of carefully and observantly removing piece by piece until the whole is completely dissected, and we shall find but little difficulty in reconstructing what we had before laboured in vain to build up. The simile, it must be admitted, is imperfect; but true it is that before we can synthetize we must understand well how to analyze; and it is not improbable that when all that the searching mind of man can accomplish in the unravelling of material complications has been effected, and when he sees with tolerable intelligence all the processes of nature in the dissolution of her living forms, and is able with the aided or unaided eye to follow her formative processes; when he has been able to accomplish all these things, then it is not improbable that he may become skilled enough to construct the organized tissue in which vital force (let physicists call it what they will) finds a medium of action, just as he is now capable of preparing those mechanical contrivances which are rendered self-moving by the obedient forces of the physical world. One important step has been already made in this direction, for if he cannot yet form that plastic material, that protoplasm, in which life is first seen to dawn, at least he has robbed nature of her exclusive privilege to create substances which it has hitherto needed vital influences to produce. If he cannot usurp her powers so far as to make organized tissues, at least he has succeeded in constructing synthetically some of the proximate principles of which they are constituted, and it is to the present state of his knowledge and attainments in this branch of chemical science that we now propose to direct attention. When we compared the analytical and synthetical experience of our investigators with that of an ordinary person taking to pieces and reconstructing a well-known puzzle, we said that the simile is imperfect, for the power in man to build up organic substances is not the immediate sequel to his analytical experience. "The pulling to pieces of these substances," says Wanklyn, "is a matter of very little difficulty: more than fifty years ago chemists could do thatbut how to put the pieces together again is a much more difficult task. Sugar consists of 72 parts by weight of carbon, 11 parts of hydrogen, and 88 parts of oxygen. We may bring together carbon, hydrogen, and oxygen in these proportions, and shake them up together, or heat them, or cool them, and yet we shall never get them to combine so as to form sugar. Alcohol consists of 24 parts of carbon, 6 parts of hydrogen, and 16 parts of oxygen, but no alcohol ever results from making such a mixture. Neither sugar nor alcohol can exist at the temperature to which it is requisite to raise our mixture of carbon, hydrogen, and oxygen, in order to get chemical action to set in. At ordinary temperatures the organic elements will not enter into combination, whilst at high temperatures they combine it is true, but yield comparatively very few compounds." That the chemist has, however, been able, by a series of synthetical operations, to build up alcohol-a product which previously nature alone was able to furnish-will be seen presently; and not alone has he succeeded in fabricating this organic material, but many others, both in the plant and animal realm, the chief of these being oxalic acid, resembling that extracted from the common wood sorrel; acetic ether, the flavouring substance of certain wines (consequently the product of the grape-plant); amylic and butyric ether, the essences respectively of the pear and pineapple, in the vegetable kingdom; and in the animal kingdom, the well-known substance glycerine, the sweet principle of animal fats and oils; lactic acid, the acid of sour milk; formic acid, the product of vital action in ants; and leucine, a fine white powdery substance resulting from the treatment of certain organic tissues with dilute sulphuric acid. The last is ordinarily found in the spleen, pancreas, liver, bile, kidneys, and salivary glands. All these and many allied substances have of late been synthetically prepared from inorganic elements; but the first organic material thus artificially constructed was Urea, an excretory product of the mammalia, and this was effected by a German chemist (Wöhler), in the year 1828, in the following manner:-" Cyanide of potassium-a body which can exist at a red heat, and which can moreover be formed directly from its constituents, carbon, nitrogen, and potassium-was oxydized |