thi voflour Kind: of Air, 44.7 



Appeared, and was frequently renewed, by brilliant points from the ftirface of the 

 wfeter; tfome of which produced the illumination through the air. I faw the fame 

 thing feveral times, as did likewife a number of fpedators, who were much furprifed at 

 the effe£V. 



I at firft fuppofed that the water of the phial in which the phofphorus was placed might 

 hold fufpended certain fmall particles of the phofphorus, which were afterwards diflblved 

 by the atmofpheric air of the vefTel ; and that fome part of this phofphorus, afterwards 

 taking fire in confequence of the agitation of the water, might produce through the whole 

 of the air, the flame I have here fpoken of. But the ready combullion of phofphorus in 

 atmofpheric air at the temperature of i8 degrees contradicted this explanation; not to 

 mention that it was dilEcult to conceive that the air fliould occaHon the folution rather 

 than the combuftion of this fubftance. I could not even fuppofe that the atmofpheric 

 air of the veflel was decompofed by the phofphorus dilTolved in the water, or by very 

 fmall particles of this fubflance which might float upon the liquid -, fo that the azotic gas 

 remaining alone might adl: on the phofphorus, partly dilTolving it, and by this means 

 conflituting a phofphorated gas, which might fhine by the agitation of the water, in con- 

 fequence of the difengagement of a quantity of oxygene futEcient to occafion combuftion. 

 For I had often obferved that, when the phial was uncorked with the greateft care, in order 

 to avoid any agitation, there was no production of flame notwithftandiiig the accefs of 

 atmofpheric air ; but the phofphorefcence appeared immediately upon agitating the phial, 

 whether tlie phofphorus had or had not a communication with the air of the atmo^ 

 fphere. 



On one occaGon, when I had fix phials prepared in tli^s manner, and obferved them for 

 fome time in the dark, I faw that fome of them afforded a flame fpontaneouily, and 

 without agitation. 



1 attributed this flame which appeared in the air of the phials, containing water charged 

 with particles of phofphorus, to a combuHion and inflammation of -the phofphoi us, produced, 

 at the inllant of the agitation of the furface of the water, by the immediate folution of 

 this combuftible in the atmofpheric air. I imagined that this phenomenon might be reprcr- 

 duced as long as there was any oxygene gas in the phial. It might, in fact, take place for 

 a number of times fucceflively, becaufe a very fmall quantity of oxygene is required for rile 

 purpofe. The agitation of the water appeared to me to be neceflary to detach the cover- 

 ing of phofphoric acid with which the parcels of phofphorus might eafily be covered, and 

 which might hinder their combuftion, more particularly when the phofphorus was very 

 muc!i divided ; that, if this covering fhould be fpontaneoudy detached, either by eIevatioi\ 

 of temperature or any other circumftance, the phofphorefcence mull appear in the end of 

 »he bottles even without agitation ; and that the fpontaneous flafhcs are produced in this 

 manner. 



I took a piece of phofphorus, which I caufed to burn in the air of a phial of the fanic 

 capacity as thofe employed in the foregoing experiment, at the bottom of which was a 

 Utile water. The phofphorus, fufpeiuled by a filk thread in the upper part of the bottle-, 

 hurned vifibly (the temperature being 15 degrees above zero), and, as ufual, emitted 

 white vapours, which dcfccnded to the furface of the water. \ left the phofplioru'. in 

 tlic air of the bottle until.it no longer fljone, which effcft happened in jlic courfc of the dayj 



The- 



