]0G ON RADIANT HEAT. 



Improved Tt probably may be acceptable to G. O., vol. XXV, p. 



mode of pre- jg^ to ^ e m f ormet ] pf a method of preparing a phosphorus 

 phoru. bottles, bottle, which is IB a considerable degree free from the in- 

 convenience attending those prepared according to the me- 

 thod made use of by him. 



Phosphorus, cut into small pieces and mixed with quick 

 lime in powder, answers the purpose very well. The phos- 

 phorus should be carefully dried by filtering paper, a thin 

 slice being cut may be divided into as many pieces as can 

 expeditiously be done, and each piece introduced into a 

 small bottle, with as much lime, as will surround it. Lime 

 slacked in the air, and submitted to a strong red heat, in a 

 black lead crucible for twenty minutes, is in a good state for 

 the purpose. 



The bottle, when full, may be exposed corked, to the ra- 

 diant heat of a fire, till some of the pieces of phosphorus 

 have assumed an orange tint, it will then be ready for imme- 

 diate use. But the heating is not absolutely necessary if 

 the bottle is not wanted for immediate use, and it will con- 

 tinue longer in a serviceable state. 



It is almost superfluous to observe, in using the bottle 

 the mouth should be closed with the finger as soon as the 

 match is withdrawn. 

 Bottles thus I have been in the habit of preparing a bottle by this me- 



preparedmay thod, at the conclusion of winter, for the purpose of light- 

 " t j t jy" r . ing a lamp furnace during the summer months, when I had 

 ingfour or five not convenient access to a lire. A narrow quarter ounce 

 nu>ntn>. bottle has generally continued, serviceable four or five 



months, though very frequently used. 

 Lancaster, 17 th March, 1810. P. 



VII. 



Remarks on Professor Leslie's Doctrine of Radiant Heat; 

 icith Experiments to show, that Caloric can pass through 

 transparent Media without heating them. By J. D. May- 

 cock, Esq. 



(Concluded from page 7&.) 



Proceed, Sir, to offer for your consideration a few ob- 

 iervations on Mr. Leslie's experiments, and on my own. 



If. 



