« EelmineJätka »
with oxygenated muriate of potash, that explode on being struck. The Process for Morocco Leather is a translation from the English.
The three following papers treat of the Movements and Affec tions of odoriferous Bodies exposed to Water. The phænomena are exceedingly curious. A column of camphor, placed erect in water by means of lead at its base, so as to reach above the surface, is speedily cut in two, between wind and water. The motions of odoriferous substances on water, and the means by which they are stopped, are equally amusing and extraordi nary. M. M. PREVOST and VENTURI are the authors of these observations.
Abstract of Two Memoirs on a new Method of procuring Barytes pure, and on the Properties of this Earth in comparison with those of the STRONTIAN. By M. M. FOUR CROY and VAUQUELIN. This method consists in the decomposition of nitrate of barytes by heat. The extreme solidity acquired by barytes, on being slaked, renders it probable that this earth will serve for hard and durable cements.
Abstract of Observations on the Juices of certain Vegetables, and on the Circulation of Carbone in Vegetables. By H. A, CHAPTALThe author here relates some experiments on the juice of different euphorbiums and other vegetables :-but his application of these facts to the physiology of plants is not, to us, very illustrative.
M. FOURCROY'S Discourse on the Union of Chemistry and Pharmacy occupies much of the third number. It is a judi cious and animating address.
The most important paper in Number 4 is M. VAUQUELIN'S Account of some new Processes for the Analysis of Steel and Iron. Supposing that sulphuric acid, by extricating gas from iron, caused a diminution of its carbone, the author used sulphu reous acid, and obtained much more carbone of iron. To sepa rate manganese from iron, he principally depends on fully carbonated potash, which precipitates oxydated iron, and holds manganese dissolved. Bergman much over-rated the quantity of manganese in iron.-There are other remarks in the paper, deserving the attention of philosophers.
. The remainder of the Number is chiefly filled with transla tions of papers from the German, which we have noticed, or shall notice, in our account of the originals themselves.
No. 5. has several articles interesting to mineralogists. M. VAUQUELIN shews that the leucite (white garnet) of Vesuvius contains potash as M. Klaproth had announced. M. HAUT compares the jargon and hyacinth chrystallographically. M. VAUQUELIN, after a long series of experiments on these bodies, concludes that the zirconia (earth of the jargon) is a new
body that 65 parts nearly of zirconia, with 52 of silex and a little iron, compose the hyacinth-that this earth is not attached by alkalies, but unites to acids, and with some forms soluble salts, with others insoluble, but it adheres slightly to all, With ammoniacal salts it forms soluble triple salts, is precipitated by alkaline carbonates, and redissolves in an excess of these precipitants-that it forcibly adheres to oxyd of iron-and that its great specific gravity, its slight adherence to acids which cannot be completely saturated by it, the extremely astringent and austere taste of the salts which it forms with them, and its property of being precipitated by prussiates, hydrosulfures, and acid of galls, render it analogous to the metallic oxydes.
In the same Number an opinion is given on the attempts made in this country to improve medicine by the help of pneumatic chemistry. As several of the French philosophers are medical men, and the competence of the editors of these annals is in other respects indisputable, the article will be perused with interest. It cannot (they say) be doubted that the application of different gasses will prove useful in some - indispositions. Medicine will perhaps derive from it some new specific for the benefit of afflicted humanity.'
We have also, in the present Number, a letter from M. LANDRIANI on the Means of obtaining pure Regulus of Cobalt→→→→ a Description by M. TROMMSDORF of an artificial MountainChrystal, and a Sketch of Experiments by the Dutch Chemists on the Influence of Mercury on Vegetable Life.-From these experiments, it appears that plants are killed in a few days by being inclosed in a small space along with quicksilver, and that red oxyd of quicksilver applied to their roots is highly destructive oxyds of lead, manganese, and copper are little inju→ rious. These experiments deserve repetition on a large scale.
Number 6. returns to the examination of M. Göttling's experiments on phosphorus. Some more minute phænomena are described. M. SPALLANZANI found that, on addition of hydrogene gas to oxygen which had been exposed to phosphorus, light appeared at 434° of Fahrenheit; whereas, on addition of azotic gas, a temperature as high as 59° was requisite to phosphorescence. The same naturalist gives a curious account of some petty volcanos in the Modenese, of which the eruptions were visibly occasioned by the subterraneous extrication of hydrogen gas. After the eruption had a little abated, the jets of gas were set purposely on fire. One burned quietly for 15 days. In common, the gas is discharged along with water at a spring. In cases of eruption, the fountain is widened into a small crater. This is the history of the
quondam burning well near Broseley in Shropshire, on a different scale. It is remarkable that native tar and sea salt should abound in both situations. May not something of the gas- -be discovered in the shaken same kind-viz. evolution of district of Scotland? - Observations on Alum, by M. VAUQUELIN-Others, by M. CHAPTAL.-The former demonstrably shews that, in the manufacturing of alum, the addition of potash and ammonia does not serve merely to take away the superfluity of acid. He ascertains seven combinations, argill or alumine, with sulphuric acid, taking in the triple salts into which the alkalies enter. The proper denomination of ordinary alum would, according to the present analysis, be nothing less than acid sulfat of alumine, of potash, and of ammonia.-M. CHAPTAL compares together the different sorts of alum known in commerce, and shews how their difference of effects depends on a difference of constitution.
M. VAN MONS translates a paper of M. Lowitz on frigorific mixtures. M. Lowitz finds that 4 parts of solid muriat of lime with 3 of light, dry, and fresh snow, sink Reaumur's thermometer from o° to 39°. He froze 35 pounds of mercury by throwing it into this mixture. The translator adds that the congelation of mercury is as easy to effect as that of water. The muriat of lime, simply added to water, produces considerable cold, when it contains much water of chrystallization. Reaumur's thermometer being +2°, 15 ounces added to ten ounces of water sunk the mercury to -15. This salt, being a cheap article of commerce, will probably be used in warm climates for refrigeration, where ice cannot be had. The fact is extremely interesting.
Number 7. begins with the Description of an Instrument for measuring the Volume of Bodies, without immersing them in any Liquid, by H. SAY. This stereometer, as will appear on a careful perusal of the memoir with the accompanying figures, is constructed on an original and ingenious principle.
Observations and Experiments relative to the Nitre-Mine of Molfetta, by M. M. KLAPROTH, PELLETIER, and FORTIS. Analysis of Cork and its Acid, by BOUILLON LA GRANGE.-This is the most complete essay that we have yet seen on this subject. What distinguishes cork from other vegetable substances is its convertibility, by means of nitric acid, into a peculiar resin and a peculiar acid. This acid takes metals in general from the nitric acid; and copper iron and zinc even from the sulphuric.
M. PROUST on Prussian Blue.-This gentleman endeavours to shew, in the memoir of which (as is often the case in these annals) we have only an abridgment here, that iron is suscep
tible of but two degrees of oxydation-all intermediate specimens being simply mixtures of them. These two oxyds give two sulfats; and the sulfats, on addition of Prussian alkali, two precipitates,-the more oxydated of which is the Prussian blue. On this principle, he explains some phænomena exhibited by ink, &c.-He says that the same rule of oxydation extends to other metals, and promises soon to make known the oxyd of charcoal.
We have thus presented a rapid enumeration of the principalcontents of a periodical collection, which is most honourably distinguished among its fellows. It is evident that the new numbers are in no respect inferior to the old. We wish, for the sake of science and humanity, that the editors may long continue as they have hitherto proceeded. They promise two volumes, to fill up the chasm occasioned by well-known circumstances; and to these volumes, when they appear, we shall attend with well-founded curiosity and respect *.
ART. IX. Lebens beschreibungen berühmter Männer aus den Zeiten der Wiederherstellung der Wissenschaften; i. e. Biographies of celebrated Men at the Time of the Revival of Letters. By CONRAD MEINERS. 3 Vols. 8vo. Zurich, 1795, 1796, and 1797..
N our xxiid vol. p. 526, we noticed a former work by Professor MEINERS, and expressed our hope that we should speedily receive his Biographies. They are now before us, and we sit down to fulfil our promise of analysing their contents.
A series of select lives (says the Professor) of the learned who flourished at the period of the revival of letters, appeared to me a better way of characterizing the fourteenth, fifteenth, and sixteenth centuries, than a more formal history of the resurrection of European literature; because such a history would not have admitted many details which biography invites and requires. Besides, the task of a complete historian of learning is very difficult. Few libraries contain all the works even of any single writer of great eminence in those times; much less all the documents which ought to be examined, in an attempt to ascertain the reciprocal influence of the learned on each other, and on the progressive information of their age-but if each of the distinguished literary heroes shall find a peculiar biographer, so circumstanced as entirely to know his author, the collective labor of individual biographers may supply the future historian with the requisite musæum of materials. Historical or biographical fragments, relative to those ages of new inquiry and practical innovation, are at this time peculiarly interesting; not less on account of the multitudinous and obvious resemblances, than of the still more striking and curious differences between those times and our own. However little or much I may labor in this field, I
*An advertisement in Vol. XXIII. informs us that these intercalary. volumes are just published.
shall leave to my co-operators far more to perform than my leisure will suffice to accomplish.'
'The first of these contributions to the history of letters relates to John of Ravenna, whose family-name was Malpaghino;— and if any one of the restorers of science, of the fourteenth or fifteenth century, has deserved to have his memory revived, and his name snatched from the protruded fangs of oblivion, it was certainly this favourite and meritorious scholar of Petrarch. John Malpaghino of Ravenna taught as well, and with as extensive an effect, as Petrarch wrote." He brought about, by the oral instruction which he delivered in the prin cipal cities of Italy, that great revolution in the mode of teaching and of learning which the taste of Petrarch had suggested, and which his example and his writings had begun This Malpaghino was the instructor of all those immortal men, who, at the beginning of the fifteenth century, raised from the dust, in which they had every where slept, the great works of Roman antiquity, and scattered over all Italy the novel and sound science which they contained. He influenced not only the intellects but the hearts of his hearers; and, by the dignity of his own character, which he knew how to impress on the more distinguished of his pupils, he secured to the inquiries which he cultivated, to the authors whom he recommended, and to the literary profession which he founded, a respectability and an almost sacred weight, which the startled friends of ignorance and superstition found it impossible to crush. Without him, probably, the light which Petrarch kindled would have faded into glimmering inutility; and without the men whom he animated to the investigation of the Roman classics, Manuel Chrysoloras would not have been invited to Italy to unlock the treasures of Greek antiquity. A few years' delay, and the conquest of Constantinople might have sealed up for ever the most precious of her stores.
Thus was Malpaghino a main link in the chain, which, towards the end of the fourteenth century, brought forwards the study of Roman and Grecian literature. He was the forerunner of Chrysoloras, and smoothed the way before him. It was not less providential that these two great men should exist at one time, than that they should meet in one city, and in concert deliver lectures to their common scholars:-but as Malpaghino only taught, and did not compose, so that his memory survived merely in the works of his patrons and in the gratitude of his scholars, his fame began to decline soon after his decease, and had at length so wholly disappeared, that even the learned of the fourteenth and fifteenth centuries scarcely mention him, and are often ignorant of him. Mebus was the first to revive