VOL. XLIV.] rHILOSOPHICAL TfiANSACTIONS. 213 



the mixture will be turbid, but retain no light. In these two experiments the 

 water becomes a phosphorus. 



G^ems, crystals, and glass, whether whole, or powdered ever so fine, retain 

 no light; so that neither their transparency nor whiteness contribute to their 

 becoming luminous in the dark. Of several diamonds, in all appearance per- 

 fectly the same, some were very luminous, others not at all. Of many opaque 

 substances, whether rough, polished, or finely powdered, some were luminous, 

 others not. So that it appears, that not only the external, but the internal tex- 

 ture of bodies also, may conduce sometimes to their being luminous. 



From the preceding experiments, the author is led to make some inquiries into 

 the cause of this luminous appearance; and takes notice, that almost all bodies, 

 by a proper treatment, have that power of shining in the dark, which at first 

 was supposed to be the property of one, and afterwards only of a few. How 

 this is brought about is not very easy to solve. If we suppose with some, to 

 which our author in several passages of this work seems not averse, that the 

 light from a luminous body enters and abides in the phosphori, we shall find 

 somewhat new to admire in light itself. It is no new opinion, that this fluid 

 consists of very fine particles, which are continually darted forth from a luminous 

 body, in all directions, with a very great velocity; but it has by nobody been 

 laid down hitherto, that these particles are not dissolved by the violence of their 

 agitation, nor dispersed, nor immediately cease to exist; but subsist still, and 

 adhere to what bodies come in their way, as heat does, and are the causes of 

 odours. If therefore the particles of light are not dissolved as soon as they are 

 emitted from a radiant body, but continue some time, what else is required, but 

 that we allow its atmosphere to every lucid appearance? if the phosphori shine 

 with a borrowed light, but not with their own, and that only when put in mo- 

 tion, and fired by the rays of a shining body, which some experiments seem to 

 confirm, then other new doctrines will arise. There must be then a hidden, a 

 secret principle in bodies, to be lighted up by this most subtle fire. There will 

 be in the universe a certain perpetual fire from these phosphori ; the matter of 

 which, though constantly dissipated by burning, does not waste enough to be 

 obvious to our senses. 



This work is the result of a great variety of very ingenious observations, and 

 of experiments made with the utmost accuracy ; and wherever the author makes 

 any conjecture concerning their causes, he does it with all possible decency, and 

 submission to the judgment of the learned. 



Concerning the Electricity of fVater. Bij the Rev. Dr. Miles, F. R. S. Tooting, 

 Feb. 20, 1745-6. N°478, p. Ql. 



Reflecting again on Mons. L'Allamand's experiment. Dr. M. resolved to make 



