Imágenes de páginas

Virchow. Déconverte d'une substance qui donne lieu aux mêmes réactions chimiques

que la cellulose végétale, dans le corps humain. p. 492. Gegenbaur. Recherches sur le mode de reproduction et sur le développement dans

divers groupes de Zoophytes et de Mollusques. p. 493.

The ANNALS AND MAGAZINE OF NATURAL HISTORY, vol. xii, October, November, 1853. Thos. Williams. On the Mechanism of Aquatic Respiration and on the Structure of

the Organs of Breathing in Invertebrate Animals. p. 243. Clark. On the Branchial Currents in the Bivalves. J. E. Gray. On the Teeth of the Pneumobranchiate Mollusca. Thos. Williams. On the Mechanism of Aquatic Respiration, and on the Structure

of the Organs of Breathing in Invertebrate Animals. THE QUARTERLY JOURNAL OF MICROSCOPICAL SCIENCE, Nos. 4, 5. July, October, 1853.

[Transact. Microsc. Soc., London.] Williamson. On the minute Structure of a species of Faujasina. Gregory. Notes of a Diatomaceous Earth found in the Isle of Mull. Wheatstone. On the Binocular Microscope and on Stereoscopic pictures of Micro

scopic Objects. Wenham. On the application of Binocular Vision to the Microscope. Shadbolt. A short description of some new forms of Diatomaceae from Port Natal. Legg. Observations on the Examination of Sponge Sand, with remarks on collect

ing, mounting and viewing Foraminifera as microscopic objects. Rainey, (Geo.) A method of employing artificial light for the illumination of trans

parent objects, by which it is so deprived of glare and color as to be equal in its illuminating power to the best day-light.

[Original Communications] Brightwell. On the genus Triceratium, with descriptions and figures of the species. Salter. On certain appearances occurring in dentine, dependent on its mode of cal

cification. Lister. Observations on the Muscular Tissue of the Skin. T. H. Huxley. On the Structure and relation of the Corpuscula tactus, and of the

Pacinian bodies. G. Rainey. Some observations on the illumination of transparent objects. Herapath. Paper on the discovery of Quinine and Quinidine in the Urine of Pa

tients under medical treatment with the Salts of these mixed alkaloids. Riddell (of New Orleans, U.S.) On the Binocular Microscope. Gregory. Additional observations on the Diatomaceous deposit of Mull.

Here follow short but interesting translations from the continental Journals, and Reviews.

PHILOSOPHICAL TRANSACTIONS, 1853, Pts. 1, 2. Hanfield Jones. Further Inquiries as to the Structure, Development, and Function

of the Liver. T. H. Huxley. On the Morphology of the Cephalous Mollusca, as illustrated by the

Anatomy of certain Heteropoda and Pteropoda collected during the Voyage of

H. M. S. " Rattlesnake,” in 1846-50. J. Tomes. Observations on the Structure and Development of Bone. Newport. On the impregnation of the Ovum in the Amphibia, (Second Series, re

vised.) And on the direct Agency of the Spermatozoon.

ART. X.Biography of Berzelius; by Prof. H. Rose, of Berlin.

(Concluded from vol. xvi, p. 313.) The next subject to which Berzelius turned his attention belongs to organic chemistry. It was a comparative investigation of tartaric and racemic acids. He first corrected his former analysis of tartaric acid, in which he had given an atom more of hydrogen than Prout and Hermann, and adopted the results of these chemists. But he then found that the crystallized tartaric acid had precisely the same composition as the effloresced racernic acid, and that both acids had the same capacity of saturation,-facts which, especially at that time, were in the highest degree remarkable. This was one of the first clearly demonstrated examples that bodies of different characters may have the same composition. Berzelius had, sometime before, observed a somewhat similar fact in reference to the oxyds of tin, and Faraday, a short time afterwards, in reference to the compounds of carbon and hydrogen. Clarke had also discovered the remarkable modification of phosphoric acid, which he called pyrophosphoric acid. On this occasion Berzelius combined together, in an interesting manner, what was known of these bodies, to which he gave the name Isomeric. This term has been universally adopted, now that the number of such bodies has been so greatly increased.

From this time Berzelius frequently occupied himself with subjects which are certainly of the greatest interest to every thinking chemist, and indeed for every scientific man, since they are calculated to unfold to us somewhat more fully the nature of matter. He made known his views on this subject repeatedly, both in his "Jahresberichte," and in the several editions of his “ Lehrbuch." Finally, he assumed two essentially distinct kinds of isomerism, and, in the strictest sense of the word, called those bodies only isomeric in which the elementary atoms may be regarded as grouped in different ways, forming compound bodies. These isomeric bodies may again be of two different kinds. They consist either of compounds which, with equal atomic weights, present different characters, or of compounds in which, though they possess different characters, the relative proportion of the constituents is the same, but in which the atomic weights are not equal, but twice, thrice, etc., as great as that of each other. Such bodies Berzelius termed, for the sake of antithesis, Polymeric compounds.

The other kind of isomerism Berzelius called Allotropism. It refers solely to elementary bodies, which, owing to causes not yet sufficiently understood, assume a different character from that which is usual to them, and, as it appears, retain this difference in

many combinations, where it may be the cause of differences in the character of these coinpounds. When isomeric conditions are observed in compound bodies, which consist of only two elements, combined in very simple proportions, this isomerism is, according to Berzelius, to be regarded less as owing to the different arrangement of the elementary atoms than to the allotropic condition of one or both of these elements; nevertheless, instances may occur in which both causes are simultaneously at work.

It is possible that Berzelius may sometimes have gone too far in his assumption of allotropic conditions, for there are some grounds for believing that an apparent allotropism may result merely from a different state of division. Thus, a few years before the discovery of the first example of isomerism, Magnus observed the interesting fact, that when the oxyds of iron, nickel, and cobalt, are reduced by means of hydrogen to the lowest possible temperature, the metals obtained ignite spontaneously, and oxydize when exposed to the atmosphere. This pyrophoric character evidently results from the finer subdivision of these metals, and it is destroyed when a higher temperature is employed in their reduction, which causes the particles to cohere together. The differences in platinum, according as it is reduced from its salts by the humid process, or obtained by igniting the ammonio-chlorid, and likewise the unequal combustibility of silicium, and its variable solubility in hydrofluoric acid, may probably be explained in the same way. Nevertheless, Berzelius was inclined to ascribe all these differences to allotropic conditions.

Shortly after the appearance of the paper in which Berzelius treated of bodies which, with the same composition, have dissimilar characters, Dumas went so far as to put forward the bold question, Whether many elementary bodies were not allotropic conditions of one substance, especially such as have the same, or very near the same, atomic weight, as nickel and cobalt, platinum and iridium, &c. ? Berzelius favored this hypothesis, and regarded it as befitting, that new ideas should be followed up in all directions, even when it is not possible at the same time to adhere strictly to that which is, for the moment, to be regarded as probable; for truth sometimes appears to be inconsistent at the first glance, and in any case this was a way to arrive more rapidly at the results which might follow from a new idea. Certainly, upon the other hand, it cannot be denied that the question respecting a relation similar to isomerism between elements which have analogous but still distinctly different chemical characters, belongs to a domain, where perhaps our conjectures will never admit of being put to the proof.

The next paper by Berzelius was upon Vanadium. Sefström had found a new metal in the bar-iron of Taberg, which he called by this name. He had, however, restricted his investigation to the preparation of the oxyd, or rather the acid of this metal, from the finer slags of the Taberg iron, and the determination of its distinguishing characters. He then transferred his stock of vanadic acid to Berzelius, in order that he might investigate the characters and history of the new metal. This investigation is a very extended one, and through it we have become acquainted with the new body in all its relations; whilst, as these are manifold and interesting, and as the acid has but little resemblance to other acids, it was difficult to assign to it its true position among them. In this respect the paper of Berzelius on vanadium may almost be compared with that upon selenium ; for both have this peculiarity in common, that by them we have become so thoroughly acquainted with new and hitherto entirely unknown bodies, although in both instances but very minute quantities of rare material could be employed, that subsequent investigations have added but little to our knowledge, and nothing essential. Vanadium was afterwards found at several places, although always in very small quantities. Wöhler directed especial attention to the fact, that the acid of the new metal was contained in the lead ores of Zimapan, in Mexico, in which, as early as 1801, Del Rio discovered a new metal, and called it Erythronium ; but misled by the authority of Collet-Descotils, who declared it to be chromium (with which Vanadium has certainly some similarity,) he afterwards admitted that his discovery was an error.

His next researches, which were upon Tellurium, were of a similar nature. Berzelius had already instituted experiments with very minute quantities of this metal, in so many respects interesting, but he was compelled to discontinue thein for want of material. When Wöhler sent him a considerable quantity of this rare metal, which he had prepared from the telluric bismuth of Schemnitz, he again commenced the investigation. He first shewed how this metal can be prepared in its purest state. He then prepared all the compounds of tellurous acid (peroxyd,) as well as telluric acid, discovered by him, with bases, and indeed the different isomeric modifications which these acids forin. These researches were likewise so complete, that they fully developed the history of this remarkable metal in all its relations.

The last great investigation by Berzelius, is that upon meteoric stones. He undertook this with the intention of studying these bodies, (as my brother and Nordenskjöld had already done,) as species of rocks, and, by this means, to determine what individual minerals they contained. The immediate inducement was a meteoric stone sent to him by Reichenbach, which had fallen a year previously in Moravia. But besides this, he examined three other earthy meteoric stones, and two masses of metallic iron. Berzelius inferred from his analysis that meteoric stones consist SECOND SERIES, VOL XVII, No. 49.-Jan., 1854.


entirely of such minerals as are found upon the earth, and that they certainly do not contain any elementary constituent which is not met with in terrestrial bodies. It was only in the meteoric stone of Alais that he found carbon in an unknown state of combination: this stone, when placed in water, disintegrated and fell to powder, which had a mixed smell of clay and hay. This shewed that if, as Berzelius considered, meteoric stones originated from other cosmical bodies, in their native state they could be converted into clayey mixtures, like the rocks on our own globe. He then raised the question as to whether this carbonaceous earth from the surface of another cosmical body contained organic remains, and consequently, whether there were upon its surface organised bodies, more or less resembling those on our earth? It is easy to conceive the interest with which he attempted to solve this question. This solution was not affirmative, but the results of his experiments did not justify a negative inference. Water and alkalies did not extract anything organic from the meteoric mass ; on dry distillation, however, carbonic acid, water, and a blackish-grey sublimate were obtained, but no empyreumatic oil and no hydrocarbon ; the carbonaceous matter was, therefore, not of the same nature as the humus on the earth's surface. The sublimate heated in oxygen, gave no carbonic acid or water, and changed into a white insoluble substance, whose nature could not be determined on account of the minute quantity. But to have pronounced it to be an elementary body, not originally belonging to our earth, would have been inwarranted.

This was the last extensive research made by Berzelius. His health, which, never strong, had already often necessitated the interruption of his labors, became, with increasing age, more delicate, and no longer admitted of his remaining continuously in the laboratory. He suffered, as is not unfrequent with intellectual men, especially from nervous headaches, which could not be mitigated by the most moderate living. He now begun to complain of a failing of the senses, especially his sight, and also of the weakness of his memory.

But his scientific activity did not on this account cease. He interested himself to the last for every branch of chemistry, and took the most active share in all the achievements of this science. Indeed, now that he was no longer occupied by important practical labors, he concentrated his activity more especially upon undertakings of a literary character, and with a zeal and industry which deserve the greater acknowledgment, since his bodily suiferings increased every year.

Among the products of the literary activity of Berzelius, I will here only make especial mention of the different editions of his "Lehrbuch der Chemie," and his “ Jahresberichte ueber die Fortschritte der physikalischen Wissenschaften." His other works,

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