5041 Dr. Pearson's Experiments for 
producing a white circular cloud, which in ascending expanded 
gradually, till it burst in the air. It continued to emit these 
bubbles from time to time, during an hour, and then left a grey 
sediment, which w r as phosphoric selenite and lime, and the wa- 
ter tasted strongly of lime. The same pow ; der, in hot w T ater, ex- 
ploded more rapidly and loudly than in cold, but not so violently 
as the phosphoric air obtained by boiling phosphorus in a lixi- 
vium of caustic fixed alkali. By putting this powder into an in- 
verted jar of water, I collected a quantity of the air which it pro- 
duced ; it had the properties of the phosphoric air already men- 
tioned, and, amongst others, by standing over water a day or 
two, it became no longer spontaneously inflammable, but ap- 
peared to have deposited phosphorus upon the water and sides of 
the vessel, and exploded upon applying to it a lighted wax taper. 
This powder, therefore, I apprehend, consists of phosphorus and 
lime united by heat ; it readily decomposes cold water, and then 
the inflammable air disengaged unites w ? ith, or rather suspends, 
a portion of phosphorus, and forms phosphoric air. The phos- 
phorus thus suspended by standing is deposited, and inflammable 
air alone remains ; the other constituent of water, respirable air, 
unites to another portion of phosphorus, and composes phos- 
phoric acid, which combines with lime, and forms phosphoric 
selenite. This compound of lime and phosphorus, which some 
of my chemical friends have called fulminating hepar of phos- 
phorus,* may be used to obtain phosphoric air with much more 
ease than by the usual method, f 
* In the new system of chemistry it will be called phospbur of lime. 
f Dr. Ingenhousz has devised some surprising and beautiful experiments with this- 
substance. 
