with refpect to their conftitution and method of living, who are moft liable to this difeafe, and fhews its remote or predifpofing caufes from meteorological obfervations. Led by thefe previous difcuffions and obfervations to the knowledge of the original feat of the diforder, and the matter that properly conftitutes it, he maintains, that the former is the membrana adipofa or celluJar fubftance, and the latter, the mucus of that membrane reduced to a ftate of diffolution, while the principal diffolvent of this mucus is a matter emitted by insensible perspiration, which had long been retained in the small cells of the mucous membrane. This hypothefis is fupported by clinical observations and numerous practical facts. It is alfo by fuch facts that our Author proves the real existence of an ESSENTIAL miliary fever, while he indicates the characteristics which diftinguish it from the other exanthematous fevers. Finally, he fhews, that in its principle it belongs to the catarrh, and that in its commencement and progrefs, it is inflammatory and putrid.

Mcm. VI. Concerning a Prefervative against contagious epidemical Difcafes. By M. CARRERE. This is not a new discovery, but the revival of an old one, the merit and importance of which are confirmed by new examples, and judicions obfervations. It has often been obferved in epidemical diforders, that perfons who had an habitual running or difcharge, either natural or artificial, were prefe:ved from the contagion. Our Author was the phyfician of a family in which eleven perfons were feized with an epidemical difeafe; the father alone, who had an ulcer in his leg, in a flate of abundant fuppuration, efcaped the infection. A multitude of fimilar cafes are mentioned in this memoir, on the authority of the most refpectable teftimonies. Thefe have induced M. CARRERE to recommend, as equally effectual, a draining aperture, formed by a blistering plaifter, a cautery, or a feton, which may be more efpecially neceffary to thofe who are obliged to attend or approach the perfons that labour under epidemical diforders. During a plague in the empire of Morocco, which, in the fpace of five weeks, carried off 85,000 perfons, a Jew phyfician, who took care of the fick, and many others, were faved from the contagion by the means of cauteries or iffues.

Mem. VII. C. Inoculation. By Dr. GIROD -Mem. VIII. Concerning fome Abufes that have been introduced into the Practice of Insulation, and the Precautions that are necessary in order to render this Operation as falutary and advantageous as poffible. By M. DE HORNE. We join together thefe two memoirs, though they are feparated by intervening ones in the volume before us. In the firft, M. GIROD relates the fuccefs of his practice in this important branch of his profeffion. In the fmall town of Millau in Rouerge, between the 20th of March and the 20th of June,

229 perfons (from the age of 8 months to 19 years) were inoculated without the lofs of one; while, at the fame time, of 234 perfons, who were attacked by the fmall-pox in the natural way, 32 died in the diforder, and feveral others fell victims to its fatal confequences. Among many interefting obfervations contained in this memoir, we cannot omit the mention of one which does peculiar honour to the candour and franknefs of our Author. He obferves, that those who had been inoculated by the common people, without any preparation or medical attendance, went through the disorder with more fuccefs than those who were under the care of regular phyficians. This recals to our remembrance the old proverb-that too much cookery spoils the broth; but whatever truth and wifdom there may be in this maxim, we would prefer a foup made by a cook before that which came from the hands of an oftler, ceteris paribus.

The abuses in the practice of inoculation, that are reprobated in the fecond memoir, are, 1, the attempts to diminish the number of puftules by the ufe of myfterious remedies to enervate the force of the virus, and by diverting its courfe from the skin in, order to convey it through the rectum:-2dly, A want of attention to the choice of a proper temperature of the air, equally removed from violent heat and intenfe cold.-3dly, An indifcriminate application of this practice to perfons of all ages and conftitutions.-4thly, The ufe of a variolous matter for the infertion of the fmall-pox, taken, without diftinction, from perfons of a found or vitiated conftitution.-5thly, The infertion of too great a quantity of the virus.-6thly, The neglect of a judicious preparation of the body, with feveral other abufes, for which we refer the reader to this judicious and inftructive memoir.

Mem. IX. Concerning the purgative Remedies that are good for Sheep. By M. DAUBENTON. This curious memoir is well adapted to correct an error which has hitherto prevailed in the treatment of domeftic animals. It has been thought fufficient to proportion the dofes of the remedies, that are employed in the diforders of the human fpecies, to the fize of animals, without examining by proper experiments, whether thefe remedies operate on different kinds of animals in the fame manner as they do on the human body. Experience and obfervation have convinced M. DAUBENTON that they do not; that there is a great diverfity in their effects; and that there are remedies which operate powerfully on men, and, nevertheless, produce no fenfible effect upon animals. This confideration excited him to undertake a series of experiments in order to afcertain the effects of feveral remedies for fheep, and more especially purgatives. Thefe are enumerated here, and accompanied with obfervations

and

and reflections, which will prove highly inftructive and ufefal to the proprietors and inspectors of the fleecy flock.

Mem. X. Obfervations on the different Methods of adminiftering Electricity, and the Effects they have produced. By M. MAUDUYT. This piece, which, on account of its merit and importance, has been published separately by order of government, is a fupplement to two memoirs on medical electricity published in a preceding volume. It is defigned to exhibit a full and collected view of all the different methods of adminiftering electricity, and all the difeafes to which it has been applied, with more, or lefs, or no, fuccefs. It contains little new to an English reader, as it is, for the most part, an abridgment, though a very judicious one, of M. CAVALLO's Effay on the Theory and Practice of medical Electricity, publifhed in 1780, and of Dr. WILKINSON'S Latin differtations, published at Edinburgh in 1783.

Mem. XI. Reflexions on the Effects of vitriolic Ether and nitrous Ether in the animal Oeconomy. By M. LAVOISIER. Those who make use of ether, either as a calmer, or as a remedy for head-achs arifing from bad digeftion, will find useful inftruction in this memoir, with refpect to its operation, and the method of adminiftering it.

ART. XXXI.

Della Pittura, &c. i. e. A Memoir concerning Eucauftic Painting with Wax. By M. J. M. ASTORI, Honorary Member of the Academy of Painting at Venice. 8vo. 1786.

MUCH learned labour has been employed to afcertain the

method used by the ancients in their encaustic painting. The various attempts that have been made to recover this method, by Count Caylus, Meffrs. Bachelier, Muntz, the Chevalier Lorgna, the Abbé Requeno, and other virtuofos, are well known. Whether this ancient art has been fo recovered, as it was formally practifed, is ftill doubtful. But methods that come near to Pliny's ambiguous defcription of it, have been ingeniously contrived and carried into execution with remarkable success; and M. Muntz, among others, has propofed feveral ingenious improvements in the art of encauftic painting. M. ASTORI comes laft, though not the leaft, in this feries of improvers and inventors. He obferves, that the ancients thickened their colours with wax, and this they had the art of keeping conftantly in a state of fluidity, which no modern attempts, fays he, have been able to effect without the prefence of fire. His method of producing this permanent fluidity, is fimilar to that mentioned in our fixty-fifth volume, p. 95; with which process we were favoured by a gentleman well verfed in the art of painting.

He keeps kali, or foda, in maceration, for a confiderable time, in a quantity of cold water, fufficient to cover it, fo that the water may

may become faturated with the falts of the kali. To prepare the wax, he melts it in a fmall pot, and, before it boils, he pours upon it the water of the kali, filtrated through grey paper, having previously infufed into the water between 8 and 10 drops of the beft Spanish honey. He agitates this mixture over a fire, until all the ingredients are perfectly diffolved and blended together. He then puts the wax into a veffel, where it remains in a ftate of foftnefs, like that of liquid pomatum, and fit for use. The liquidity of this mixture may be augmented by diluting it with warm water. After this part of the process is finished, the colours, mixed up with water, are diluted in the water of gum arabic, in a quantity proportioned to that of the wax. The wax-compofition is alfo diluted apart, and afterward the whole is mixed up together, and blended and incorporated into one liquid body. When mineral colours are employed, the wax muft conftitute one half of the mixture, a fourth when lac is ufed, and a third when any other colours are preferred.

Before the colours are drawn upon the canvass, it must be rubbed over with white-lead, gum arabic, and water of wax; this latter is a water, in which wax, prepared in the manner above mentioned, is diffolved. When the picture is finished, it muft be washed over with the wax water, repeatedly poured along its furface; and after being wiped, it is to be placed near a gentle heat, fufficient only to make the wax emit a little fmoke; and this warmth will make the colours rife from the canvals with a more vivid luftre. When the picture is grown cool, it is to be rubbed with a cloth, to render its furface smooth and shining.

Our Author obferves, that his wax water may be employed as an excellent varnish to preferve prints, which are expofed in frames, from the noxious impreffions of the air; and he indicates the manner of using it for this purpofe. He alfo thinks that it may be usefully employed for the preservation of pictures drawn with oil colours, and alfo of crayons. He has not yet finished all his plans for the improvement of colouring, that important branch of the art of painting, which has fuffered fo much by the deftructive influence of time: he is ftill going on with his experiments, and he has attempted a combination of the oil of poppies with wax. With this mixture he proposes to finish a piece, which, with refpect to the duration and beauty of its colours, will unite all the advantages of ancient and modern painting.

Such is the account of this work which we have received from one of our foreign correfpondents; the original we have not yet been able to procure. The reader will obferve a deficiency in the defcription of the process; though the particular quantity of the honey is mentioned, the proportions of the other ingredients are not (pecified. We have tried various proportions,

but have never been able to accomplish a union of the wax with the other ingredients. By caufticating the alkali we readily obtained a perfect folution of the wax; and we suspect that the kali afhes used by our Author had been newly burnt, and on that account were in fome degree cauftic.

ART. XXXII.

Kongl. Vetenskaps Academiens Handlinger, i. e. Memoirs of the Royal Academy of Sciences at Stockholm for the Year 1781.

WE

E fhall now proceed to give a more particular account of the principal articles in thefe memoirs, the general contents of which we barely announced in the Appendix to our 70th volume, p. 570.

Mem. I. Concerning the conflituent Parts of the Tung fien. By M. CHARLES WM. SCHEELE. The conftituent parts of this kind of iron are little known. Cronstedt calls it ferrum calciforme, terra quadam incognita intime mixtum. That on which the experiments here related were made was taken from the mine of Bitzberg, and was of a pearl colour.

We cannot circumftantially relate all the experiments made on this metal by the learned Academician, without going beyond the bounds which a multitude of other articles prefcribe to this. We shall therefore content ourselves with indicating their results. M. SCHEELE obferves, that fire made no remarkable change in the tungsten, and that neither glafs of borax nor boiling water act upon it. The folution of it by fpirit of nitre, when precipitated by alkali of tartar, furnishes a white precipitate, of an acid kind, which is foluble in boiling water, in the proportion, however, of twenty parts of water to one of the precipitate. It gives a red hue to the dye of lacmus, and is acid to the tafte.

Several experiments were made to ascertain the nature of this acid. Being dried and expofed to flame by a tube, it contracted a brownish yellow hue, became afterwards brown, finally black, and neither produced (moke, nor exhibited any indication of fufion. Being combined with borax it was changed into a blue glafs, and, tried with microcosmic falt, into fea-green glass. It Hofes gradually this colour when it is prefented to the point of a flame: a small quantity of nitre removes the colour immediately: but it returns when the blue part of the flame is directed to the ore; whence it appears that the colour is revivified by the phlogifton of the flame. When the acid of tungsten has been pulverifed and brought into ebullition with a fmall quantity of the spirit of falt or nitre, the powder becomes yellow, and, with spirit of vitriol, contracts a blue colour. When it is diffolved in water and faturated with alkali of tartar, it furnishes a neutral falt in very fmall cryftals. When it is combined with volatile alkali and fal ammoniac, it appears under the form of small