EXPERIMENTS ON INVISIBLE RAYS OF SOLAR SPECTRUM. £55 



red vapours are produced by a new addition of a fmall quan- 

 tity of the gas. The faline folulion will now be turbid : leave 

 it therefore undifturbed, and a precipitate will be depofited, 

 which is fulphur, from the quantity of fulphur fo produced we 

 may learn the quantity of fulphurated hidrogen gas which was 

 contained in the folution, for one grain of it when perfectly 

 dry, are equivalent to 3.33 cubic inches of fulphurated hidro- 

 gen gas. 



Old Compton Street, Soho, 

 July 20, 1803. 



VIII. 



Experiments on the Invifible Rays of the Solar Spectrum. By M. 

 Ritter, of Jena*. Communicated by M. Vicktred, 

 Doctor in the Univerfity of Copenhagen, to the Editors of the 

 Bulletin des Sciences at Faris, No. 73. 



A HESE enquiries form a fequel to the experiments by which Ritter's experi- 



Herfchell difcovered the exiftence of invifible calorific ravs ^^ on invi * 



J hole rays, 

 beyond the limits of the folar fpectrum. The experiments of 



M. Ritter prefent a very fimple method of proving the exift- 

 ence of thefe rays by the exhibition of a very curious property 

 which he fays is peculiar to them. 



He placed muriate of filver without the folar fpectrum and The rays in the 



next to the violet rays. This oxide became blackened in a c ? n , fine of the 

 n_ • • i n-n i i • i rt -n violet reduce or 



lnort time, it became ltill deeper in the violet rays, ltill more blacken the 



in the blue, and fo on. muriate of filver 



On the contrary, placing muriate of filver a little blackened thofe near the 



next to the red rays, and without the fpectrum it quickly be- re ?. render . it 

 ,..-.. .., • , white or dif- 



came white, that is to lay, it was diloxigenated. oxide it. 



According to M. Ritter, thefe experiments may be per- Combuftion an4 

 formed very Well with phofphorus : by letting fall on it the in- e * tin & ,on of* 

 vifible ray neareft to the red, it inftantly emits white vapours; the (ame means, 

 but tiie invilible rays neareft the violet are thrown on the fame 

 phofphorus, it inftantly becomes e\tingui(hed. 



From thefe fafts, M. Ritter concludes, that there exifts with- 

 out the fpe&rum, and at its two extremities, invifible rays 

 which po.iefs the property of affifting oxigenation and difoxi- 

 genation. 



* From the Bulletin des Sciences, Germinal, An. XI. 



The 



