compound of hydrogen, nitrogen, and carbon; hydrobromic; fluoric-acid; ferro-cyanic acid; sulpho-cyanic; hydro-selenic; hydriodic: xanthic. Even if fluoric be omitted, here are nine undeniable acids, and all without a particle of oxygen in their composition. Again, the mere fact of calcination should have prevented him from so generalizing, for all calces contain oxygen, and many of them have no acid qualities. Indeed, his own conjecture, since fully confirmed by experiment, that the fixed alkalis are oxides, is a still more striking disproof of his theory; for it appears that he might just as well have called oxygen the alkalizing principle as the acidifying, or rather much better, since all the alkalis save one contain it and the alkaline earths to boot. But he also should have recollected that no acid of them all contains so much oxygen as water, and yet nothing less like an acid can well be imagined. We now have still further instances of the same kind against this theory, and which might justify us in calling hydrogen the acidifying principle as well as oxygen. Upwards of two hundred acids contain hydrogen either with or without oxygen present. Hence he might really have reckoned hydrogen the acidifying principle upon fully better grounds than support his choice of oxygen; and the truth appears to be, that there is no one substance which deserves the name. It is, then, quite clear that M. Lavoisier committed a great error in his induction, and that he framed a theory which was in the extent to which he pressed it wholly without foundation—not merely without sufficient proof from the facts, but contrary to the facts. Newton gives it as a fundamental rule of philosophising, that we are to state the inferences from phenomena with the exceptions which occur, and if a first induction should be made from imperfect views of the phenomena, then to correct it by the exceptions afterwards found to exist. But from this rule Lavoisier has departed entirely because, though subsequent experiments have greatly increased the number of the exceptions, yet there were many striking ones at the time he formed his system, and these were left out of view in its formation. After all the deductions, however, which can fairly be made from his merits, these stand high indeed, and leave his renown as brilliant as that of any one who has ever cultivated physical science. The overthrow of the Phlogiston Theory, and the happy generalizations upon the combinations of bodies, which we owe to his genius for philosophical research, are sufficient to place him among the first, perhaps to make him be regarded as the first reformer of chemical science, the principal founder of that magnificent fabric which now fills so ample a space in the eye of every student of nature. APPENDIX. Acids known to contain no Oxygen. Muriatic acid, (Hydro-chloric; Chlorine and Hydrogen.) Prussic acid, (Hydro-cyanic; Hydrogen, Nitrogen, and Carbon.) Bromine. Hydro-Bromic acid, (Bromine and Hydrogen.) Ferro-cyanic acid, (Iron, Azote, Carbon and Hydrogen.) Hydro-selenic, (Selenium and Hydrogen.) And at least 150 more; as oxalic is perhaps the only vegetable acid which has no hydrogen. SIR JOSEPH BANKS. It is rare to observe a name among the active and successful promoters of science, and which yet cannot easily find a place in its annals from the circumstance of not being inscribed on any work, or connected with any remarkable discovery. Almost all the philosophers of both ancient and modern times have left us writings in which their doctrines were delivered, and the steps made by their labours were recorded. The illustrious exception of Socrates almost ceases to be one, from the memory of his opinions being preserved by two of his disciples in their immortal works; and the important discoveries of Archimedes and of Pythagoras are known distinctly enough in the books of ancient geometry, to leave no doubt resting upon their claims to the admiration and the gratitude of all ages. The lost works of the ancient geometers evidently afford no exception to the general remark, since they once existed, and contained the discoveries of their authors. It must, however, be observed, that the circumstance of a cultivator of science having left no works to after ages is merely accidental. He may have enriched philosophy with his achievements, and yet never have recorded them himself. Thus, had Black only made the great discovery of latent heat and specific heat, he would have been justly considered in all times as one of the greatest benefactors of natural science, and yet the history of that splendid discovery would only have been found in the memory of those who had heard his lectures; his only work being confined to the other discovery of fixed air, and the nature of the alkaline earths. To take a yet more remarkable instance;-how little of Watt's great and lasting fame depends on any written work which he has left! The like may be truly said of Arkwright; nay, the most important of inventions, the art of printing, is disputed by two names, Coster and Guttenberg, neither of which is connected with the composition of any literary work whatever. As men who have by their researches advanced the bounds of science,-"inventas aut qui vitam excoluere per artes," may never have given any written works to the world, and yet merit a high place among the greatest philosophers, so may others who have filled the less exalted but highly useful sphere of furthering the progress of the sciences or the arts, deserve a distinguished place among philosophers for the same reason which entitles authors to such a station, although they may never have contributed by any discoveries to the advancement of the sciences which they cultivated. The excellent and eminent individual whose life we are about to contemplate falls within this description; for although his active exertions for upwards of half a century left traces most deeply marked in the history of the natural sciences, and though his whole life was given up to their pursuit, it so happened, that with the exception of one or two tracts upon agricultural and horticultural questions, he never gave any work of his own composition to the world, nor left behind him anything, beyond his extensive correspondence with other cultivators of science. It is from this circumstance that not even an attempt has ever been made to write the history of Sir Joseph Banks. And yet, what so worthy of contemplation as the history of one who loved science for its own sake, who delighted in the survey of important facts connected with the study of nature, or tracing interesting truths belonging to the same branch of knowledge; whose pursuit of knowledge was wholly disinterested, not even stimulated by the hope of fame as the reward of his labours? |
