PROCEEDIKGS OF THE IIOYAL SOCIKTV- 



67S 



paper is placed on tinfoil, and rubbed wiih clastic gum, 

 and although the tinfoil is not insulated, sparks are pro- 

 duced on raising the paper. Dr. Gibbes concludes with 

 sonic arguments against the dottrine of the decomposition 

 of water; and advances as a probable opinion, tliat oxygen 

 and hydrogen gas are composed of water as a basis, united 

 with two other elements, which, combined, form heat. 



The meetings of the 28th January, the 4th and nth 

 February were principally occupied by a paper on the hy- 

 peroxygenired muriatic acid, by Richard Chenevix, Esq. 

 F.R.S. 



Mr. Chenevix, after adverting to the observations of Bcr- 

 thoUet and Mr, Hoyle, proceeds to relate a series of his own 

 experiments, made in order to investigate minutely the com- 

 position and properties of the hyperoxygenizcd muriatic 

 acid. It was already known that, in the oxygenized muriate 

 of potash, the acid contains much more oxygen than in its 

 separate form. Mr. Chenevix finds that the simply oxyge- 

 nized acid contains, in 100 parts, 65 of common muriatic 

 acid, and is of oxygen. BerihoUet, from a less accurate 

 experiment, imagined that it contained only 10 per Cent of 

 oxygen. But the hyperoxygenizcd acid, which is the sub- 

 ject of the present paper, appears to consist of 30 parts only 

 of muriatic acid, and 64 of oxygen. 



; Mr. Chenevix has not succeeded in obtaining the hyperoxy- 

 genizcd muriatic acid in a separate state. In treating the hy- 

 peroxygenizcd muriate of potash with concentrated sulfuric 

 acid, a violent explosion took place, upon the application 

 of heat : this was avoided by adding the salt gradually to the 

 acid, or by using the diluted acid. In the order of affinities 

 this acid appears to stand next above the benzoic : it changes 

 blue vegetable colours to red. When the salts formed of it 

 are decomposed, by the addition of the sulfuric, nitric, or 

 muriatic acids, a flash of light is observed; hence Mr. 

 Chenevix takes occasion to question the Lavoiserian doctrine, 

 of the light in combustion being supplied by the oxygen 

 gas consumed -. and in confirmation of his remark he ob- 

 serves that plants, growing in the dark, contain a great 

 proportion of mucilage, and that mucilage burns without 

 emitting any light. The sudden explosion of many com- 

 bustible substances with hyperoxygenizcd muriate of potash, 

 when thrown into an acid, led Mr. Chenevix to attempt the 

 combustion of diamond powder in the same way : but this 

 experiment did not succeed. 



Mr. Chenevix has examined very minutely the various 

 salts formed by this acid in combination with alkalis, earths, 

 and metals. He finds that it has not, like some other acids, 

 a power of carrying over a portion of silex when mixed 

 with other earths. He combined it with metals by suspend- 

 ing their oxids in water, through which the gas was passed: 



VOL. II. 



and he found that, like the nitric acid, it tontairted loo muclj 

 oxygen to unite with the whole of the red oxid of lead ex- 

 posed to it. He observes that the nitric and other acids ap- 

 pear to stand lower in the scale of elective attraction to the 

 metallic oxids, in proportion as they dissolve the pure mctaU 

 more readily. Mr. Chenevix unexpectedly procured the 

 hyperoxygenizcd muriatic acid in submitting platina to the 

 action of the nitromuriatic acid. Pursuirig the analogy 

 suggested by Mr. Bcrthollet, of the three states, of sulfur, 

 the sulfureous, and sulfuric acid, Mr. Chenevix proposes to 

 appropriate to the common muriatic acid, the term muriatic 

 radical, or some equivalent denomination, and to call the 

 acid in the two stages of oxygenization here described, the 

 muriatous, and muriatic acid respectively. 



On the 1th February, a letter fiom Dr. Maskelyne an- 

 nounced that he had observed the new planet of Mr. 

 Piazzi passing the meridian between three and four o'clock 

 in the morning, having about las" 43' right ascension, and 

 1 2° 38' north declination, appearing like a star of the eighth 

 magnitude. 



Another letter, from Mr. von Zach, was read, informing 

 the Society that he had observed this planet at Seeberg on 

 the 7th of Decemberj withm half a degree of the place be- 

 fore determined in his journal. Mr. Olbcfs saw it at Bre- 

 men on the 2nd of January. With a iKJwer of above 120, 

 it presented no observable disc. 



On the lith, a second letter from the Astronomer Royal 

 informed the Society that he had repeated his observation 

 of the new planet, so as fully to ascertain its motion. It 

 appeared to have a visible disc when on the meridian, and 

 viewed with a power of 50. When the air was very' clear 

 the disc was round and well dofinsd, but somewhat smaller 

 than tliat of the 34th of Virgo, a star of the (5th magnitude 

 near it. Dr. Maskelyne observes that the smallness and 

 roundness of the a])pcarancc of the disc of the fixed stars 

 is a good criterion of the clearness of the air. 



Another letter, from Alexander Aubert, Esq. F. R. S. 

 was also read. Mr. Aubert discovered the planet •Ceres 

 on Sunday morning, having about 188" 41' right ascension 

 and near 1 3° declination, its motion at present being retro- 

 grade. 



On the 18th of February a letter from Mr. von Zach was 

 read, containing a continuation of his observations on the 

 planet Ceres, and mentioning an account from Mr. Harding 

 that two faint spots had been seen, at the distances of 20 

 and 35 seconds from this planet, which it was conjectured 

 might possibly be satellites : although the fact had not by 

 any means been ascertained. 



Dr. Herschel sent an account of the appearance of the 

 new planet, as viewed through his telescopes. He had 

 4 B 



