ALBERT VON HALLER.

the deep sea receives the rain of heaven, and woos back again the clouds which erewhile rested on its own bosom, so does the world absorb into its own being the human wisdom which is made up of emanations from Deity and experiences from earth. That which a man owes to his time, should always be paid back again with full interest. Our life is made up of the thoughts and acts of all the generations which have preceded us. The harvest of the soul is like the fruits of the husbandman, gathered from a soil made up of the wrecks of ancient vegetation. It is only in the front that our horizon is bounded; behind us the view is illimitable. With the characters of progress inscribed upon all things, we will not believe that the influence of change is resistless. Ignorance will soon become no longer possible. To him who has an eye, sun, moon and stars, are of necessity visible, though the beholder should have no veneration for the Creator; and in like manner the questions of knowledge will force themselves upon our notice, whether we wish it or not. The honest preceptor told his kingly pupil that there was no royal road to geometry: yet we travel on the broad highway, whilst our ancestors journeyed on the bridle paths. Not a boy of decent ability, now conning his daily tasks, but who, if he has a taste for the study of astronomy, is wiser than Newton; not a diligent chemist's apprentice, who is not qualified to give lessons to such as Friar Bacon; not an engineer's assistant, who could not remove the difficulties which perplexed the mind of Watt. These men started forth in advance of their time; they rushed into the wilderness, and there perished, their treasures marking the site of their burial places; and the world came up, possessed itself of their wealth, and is still marching onwards-preceded, as ever, by the self-devoted men who are the first to spy out the fertility of the land, though doomed, in most instances, like Moses, to die upon the summit of Pisgah.

The poet writes his own epitaph. We appropriate his wisdom; but the beauty which he incorporates with our nature, we only share in common with the giver. It is different with the man of science, who has only a life interest in all which he produces. His individuality is lost; he depends upon the world's gratitude for the bare remembrance. The silk-worm spins and dies, and the result of its labour brings to mind no thought of its existence; but who can stand upon the coral rock, without musing upon the wondrous organisation of its insect builders?

The beauty belongs to the man-the truth to the species. We do not read Harvey for an explanation of the laws affecting the distribution of the blood, although it was in his writings that the world first saw the recorded discovery. Yet we read Shakspere to ascertain the deep philosophy of Hamlet and Lear, because we cannot obtain the knowledge elsewhere. To know what the poet taught, we must still turn to the poet's pages; whilst the

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student who now learns on the threshold of the temple of science, that the blood circulates through the human frame in ceaseless ebb and flow, has never, perhaps, troubled himself to ask whether it is really true that this law of nature was first observed by one Harvey, who was born a long while and was treated as a quack by his contemporaries.

ago,

Of this class of worldly benefactors, belongs Von Haller, who was born at Berne, a Swiss Canton, October 16th, 1708. His father was a man of fortune, and had the rare felicity of discovering, in his lifetime, the genius of his son. The delicacy of young Haller's health, favoured his love of study, the advantages of which were improved to the utmost by habits of the most careful industry. He was accustomed to make notes of all he read, and at the age of nine, used to write down every day all the unusual words which he met with. At ten he is said to have composed verses in Latin, and given other proofs of the possession of precocious ability.

His father destined him for the church, but his own inclinations, which were not opposed, led him to the study of physic; and after some preliminary instruction, he went to the university of Leyden, at that time under the superintendance of the famous Boerhaave, and the scarcely less celebrated Albinus. He had afterwards the opportunity of profiting by the tuition of Cheselden, and other eminent men; and, returning to his own country, set down to practice as a physician; but the offer of an opportunity to the professorship of medicine, anatomy, botany, and surgery, at the university of Gottingen, by George II., drew him away from his native place, to which he returned in 1753, after an absence of eighteen years. He was now in the enjoyment of European fame. He corresponded with all the learned societies, and wrote upon all subjects with elegance and extraordinary facility. His professional pursuits never interfered with the discharge of the active duties, which, as an eminent citizen of the republic, he was often called upon to perform; but despite this varied excellence, his fame now rests upon his discoveries in medicine, which are thus detailed in that extremely useful work, the Penny Cyclopædia from which we take the liberty of making an extract:

Excluding all the metaphysical explanations which Van Helmont and Stahl had invented, and all those deduced from mechanics and chemistry, which were not clearly sufficient for the phenomena ascribed to them, he sought for powers peculiar to the living body, which he believed must govern the actions which he found occurring only in it. These he thought might be restricted to two-sensibility and irritability; the former seated in the brain and nerves, the latter in muscular fibre. In this he had indeed been partially anticipated by Glisson, who perceived the necessity of admitting an inherent property in muscular fibre, by which its contractions take place under the influence of certain stimuli, but the laws of this property, and the distinction between it and elasticity, had never been at all clearly determined. Haller thus illustrated these properties: the intestine removed from the abdomen, or a muscle separated from the body, is irritable, for when pricked or otherwise stimulated, it contracts, yet it is not sensible: the nerves, on the other hand, are sensible, but not irritable; for, when stimulated, though the muscles to which they are distributed are thrown into action, they themselves do not exhibit the slightest motion. Hence irritability, he said, cannot be derived from the nerves, for it is impossible they should communicate what they do not possess themselves; but he attributed a nervous power to some of the muscles, as a necessary condition of their irritability, and supposed it

to be conveyed to them during life from the brain through the nerves, and to govern their actions under the influence of certain undetermined laws. Proceeding to investigate further the laws of irritability, he found that it differed in intensity and permanency in different parts of the body. He found that it continued longest in the left ventricle of the heart, next in the intestines and the diaphragm, and that it ceased soonest of all in the voluntary muscles, and by reference to this superior degree of irritability, he explained the constant action of the heart and diaphragm even during sleep. He denied all irritability to the iris, and believed that the action of light upon it takes place through the medium of the retina, a view since proved to be perfectly correct. He supposed the arteries to be supplied with muscular fibres, but that the cellular tissue around them prevented any motion from taking place in them, and he explained the accumulation of blood in an inflamed part, partly by the contraction of the veins, and partly by the diminished contractibility of the arteries. He endeavoured to prove by experiments that the tendons, the capsules of joints, the periostrum, and the duramater are entirely insensible, and that the pain which occurs in diseases of those parts ought to be referred to the affection of the nerves distributed to and around them; and in these and some other tissues which he held to be destitute of irritability, he admitted a force analogous to elasticity, by which they contracted slowly, and in a manner altogether different from muscular tissue when divided or exposed to cold, &c.

"Such is a sketch of the great doctrine of irritability and sensibility on which Haller based all the phenomena of life, and around which he arranged all the facts of physiology known at his time, in his 'Elementa Physiologia.' It gave the first impulse to the study of the laws of life as a separate and exclusive science; and, though in some parts erroneous, and in many insufficient, it still contained enough of truth to form a firm basis for the observations collected during many successive years. His doctrines were strongly opposed by Whytt, and others; and, in the controversies that followed, numerous new facts were advanced, and the most important additions to physiological knowledge rapidly made. It was soon shown that the restriction of the vital powers to two, as defined by Haller, was much too exclusive; for, that there were many parts which, though they gave no evidence of possessing either of them, were not the less alive; while others, to which Haller refused these properties, gave sufficient demonstration of possessing them, when excited by other and appropriate stimuli. Hence, first originated the discovery of the fact, that for the action of each organ a peculiar stimulus is required, and that each tissue has w. Bichat, who illustrated it most completely, called a vie propre.

"But even if Haller had not attempted to establish any such great generalization of vital phenomena as this, his learning, and his admirable mode of studying physiology, might have been sufficient to obtain for him a reputation nearly as high as that which he always enjoyed. Possessed of a competent knowledge of all the sciences which could throw any light on the actions occurring in the living body, he pointed out, in numberless instances, what part of them was to be attributed to the laws of inorganic matter, and what to those peculiar to the state of life; while he carefully avoided admitting any of the former as sufficient by themselves to explain the whole of the latter, which had been the chief error of nearly of all his predecessors. He rarely drew any conclusion respecting the mode of action of any organ, or part in the