652 PHILOSOPHICAL TRANSACTIONS. [aNNO 1683. 



If we compare these appearances with lightning, we may observe that hght- 

 ning, which comes at intervals, passes uninterrupted the most condensed clouds 

 and is not extinguished or obstructed by the greatest storms or cataracts of 

 water; but like the beams of the sun, or any other fire, freely passes through 

 glass and water. 



This phosphorus in the abovementioned state emits those flashes of light 

 only in warm weather, a certain temper of the air being necessary to produce 

 the effect, for in the winter or cold weather I never observed it. — The warm 

 season of the summer is most productive of lightning. 



The abovementioned flash of light is not apt to kindle or burn any com- 

 bustible matter, as I found by holding my finger in it unmolested; but not 

 trusting to that, I held in the flame, paper, flax, and such materials as are apt 

 to take fire, which it did no more than when we projected the light of the 

 moon by a concave glass on the like bodies. — Such an inoffensive flame that of 

 lightning is generally observed to be. But 



The matter of the phosphorus, whilst in a more condensed body, will easily 

 be accended by the warmth of the air, or by the immediate beams of the sun, 

 and then will burn very furiously, with such a penetrating fire as will not easily 

 be extinguished. — So lightning, when condensed or contracted, and wrapt up 

 in a vehicle of air, so that it does not so easily diffuse itself through the yield- 

 ing aether, will then set fire to houses, trees, &c. and do great mischief. 



The phosphorus, whilst burning, acts the part of corrosive; and when it 

 goes out it resolves into a menstruum that dissolves gold, iron, and other 

 metals. — Thus lightning melts down gold, iron, lead, and other metals.* 

 ExPT. 11. By mixing tiuo Liquors, actually cold, to produce such sparkling and 



Jiery Bodies, as are not only visible in the Dark, but at Noon-Day, in the 



enlightened Air. 



This experiment was thus made. We took between 10 and 20 grains of 

 the solid phosphorus, and caused it to melt in as much water as would just 

 cover it, which was about a drachm: after it was actually cold we poured it 

 into 2 oz. of oil of vitriol ; the mixture being well shaken together, it first 

 lieated, and then threw up sach fiery balls, that like so many stars adhered to 

 the sides of the glass, and continued to bum for some time. 

 ExPT. III. By the Addition of an Oil to the foregoing Mixture, to produce 



a Flame. 



This is done by only adding a small quantity of oil of turpentine. With- 

 out shaking the vessel, the mixture takes fire, and burns very furiously. This 



* Modern discoveries have furnished a more satisfactory phenomenon to compare with lightning, 

 namely, that of electricity. 



