Cavendish

6. Ai diocesan V Me ideteerological•astriments used at the Boyd &dais Hose. Phil. Trot 1776. P. 17A. ,Of the thermometers it is observed, that they me adjusted by surroomang the tubes with wet olothe or with Menne, and barely immersing the bulbs ita the water; since .a variation of two or three degrees will often ewer, if these precautions are gleamed, For the correction of the heights of Oro. meters,owe lore Lord Chillies Carendides Yank d the depression arising fnam capillary sedan. The itariation complies was found to exhibit a deviating from the meridian el' gamier in the home of the &eyed them he agepen garden in 'Warhorse* Street.: -there was mho a mean error df about? the indications of the•ipping needle; but it was dl Solt to ascertain the dip, without being bade to an irregularity, which often .amounted to Moe 7. Report ef the .Cosnmeitine appoisted to smite Oho hest Method of adjusting il'heresonseters. Plrii Trans. 1777. P. 816. This :paper is signed by Nr Cavendish and six other members, hen it is paned. pally a continuation of the preceding. It cones eery soeurate rules for she deternioatioa of the bol tag point, and tables for the commies of suunsid• able deviations from them : establishing lge Mho as the proper height of the barometer for nudist the experiment, if only steam be employed, and fas if the hall be .dipped in the 'water: bat with sil precautions, occasional variations of half a hex mere found in the results.

8. An Amelia • of a New Rmersonseter. Phil. Trans. 1788. P. 106. Mr Cavendish was aware ofithegrat difference in the results of endionietairdemerionts with nitrous gas, or nitric .onyd, according to the afforest modes of mixing the elastic efluids ; Adis justly attributes than to the difesent :degrees If mygenination of the acid that is donned. Bs he found that when the method employed 'nu the writ the results were perfectly =Monis ; and he suer in this miner that there was mescal* alA hemlock the constiment.parts of the souspion sender chtmestances the oast dissimilar the sir If Lear" with silks fwea busuing is the winter, 40 Peering with the *wheat *gems a the country. He . observed -the utility of the. Bid, furets of pawn and of iron for procuring plalogistir Bated air; but he dote not seem to have employed them as testa of the quantity of this gas contained is a given mixture.

e. Observations on

Mr Hutehina's Experimental°, determining the degree of Cold at *Mai Quielatir friars. RhiL Trans. 17113. P. WS. In experi. matte of this kind, many precautions are 'memory, principally en account of the contraction of the metal at the time of its congelation, which was found to amount to about of its Wit ; and the results which had been obtained, were also found to require Some corrections for the errors of the scales, which reduced the degree of cold observed to 39° below the zero of Fahrenheit, or 71° below the•freesing point, answering to of the centesimal scale.

In speaking of the °voltaic* of bast during coup/ Isiah be calls it " generated" by the substances, and observes, in a nett, that Dr Black's hypothesis of capacities depend& " on the supposition that the beat of bodies is owing to their containing more or less of a substance called the matter of hest ; and as" he thinks " Sin lease *pixies, that heat consists in the internal motion of the particles of bodies, much the most probable," be C1100400 " ii use the expression beat is generated," in order to avoid the appearance of adopting the more modern hypothesis; and this persuasion, of the nonexistence of elementary beat, be repeats in his next paper. It is remarkable, that eau of the aria of Sir .1Itunplity Davy a ohjects, at the very begioaieg.of his singular, ly gamer of reared investigation and fon* nate discovery, was the confirmation of this Ohne* forgotten opieion of Air eevendish; and for this pu pass ha devised the vary ingenious experiment of melting two pieces of ice by their mutual friction in a room below the freezing temperature, which is certainly incompatible with the commie dnetrine of coterie, unless we admit that calorie could have ex. istedin the neighbouring bodies in the foten of cold, or of something else that could be converted We caloric by the operation ; and this transeautadoit would still he, nearly synonymous :with genaratiosk in the, sense here intended. However this :may hik it, is certain that, notwithstanding all the merit meats of Court Rumford, Dr naldelt, and others, air Humphry has been less succeesful ie persuading his contemporaries of the truth of Mr Caveudish's dectriae of heat, than in establishing the probability of his opinions respecting the meriatic acid.

10,

Experiments on Air, Phil. Trent, 1784. P. 119. Thin paper contains an account of two of the greatest discoveries in . chemistry that have aver yet baeen made public the composition at wailer, and that of the nitric acid. The author first establishes the radical djffereace of hydrogen. from nitrogen or aaote ; he then -proceeds to relate his experiments 40 the combustion of hydrogen with oxygen, which bad partly been su•,.g by a cursory observation.

of Mr _Wahine,

.urer on Natural linlompbA end which prove that pure water is the remit of, the proems, provided that no nitrogen •be. present.. These experiments titers first, made ie .17111, and were :then ustationecl to Dr Priestley ; and when they were Boo gouuumicatecl to Lavoisies, he fouusi some dilft, culty in believing them to be accurate. The &maul series of experiments demonstrates, diet when phi°. &jacketed air, or nitrogen, is present, in the some nitric acid is produced; and that thine. acid anti' be obtained from atmospheric sir, by the repeated operatiou of the spark.