Chemiluminescence 433 



on readmitting the air it returns again to its former dulness. Endeavor- 

 ing to blow it up to a flame with a pair of bellows, it seemed to be quite 

 extinguished; as it was a good while before any light appeared. 



As a member of the Royal Society, John Evelyn (1641-1706) 

 witnessed the new experiments on phosphorus. On December 13, 

 1685, he wrote: " 



Dining at Mr. Pepys's, Dr. Slayer shewed us an experiment of a wonder- 

 ful nature, pouring first a very cold liquor into a glass, and super-fusing 

 in it another, to appearance cold and cleare liquor also; it first produced 

 a white cloud, then boiling, divers coruscations and actual flames of fire 

 mingled with the liquor, which being a little shaken together, fixed 

 divers sunns and Starrs of real fire, perfectly globular, on the sides of 

 the glasse, and which there struck like so many constellations, burning 

 most vehemently, and resembling Starrs and heavenly bodies, and that 

 for a long space. It seemed to exhibite a theorie of the eduction of 

 light out of chaos, and the fixing or gathering of the universal light into 

 luminous bodys. This matter or phosphorus was made out of human 

 blood and urine, elucidating the vital flame or heate in animal bodys. 

 A very noble experiment. 



Another colleague and an assistant to Boyle brought over from 

 Germany, was Ambrose Godfrey Hanckewitz (1660-1741), whose 

 observations were published at a later date and will be presented in 

 the next section. 



EIGHTEENTH-CENTURY EXPERIMENTS 



Most of the phosphorus of the early eighteenth century was pre- 

 pared by Ambrose Godfrey Hanckewitz, ^^ who sold it for three 

 pounds sterling an ounce. He had tested practically every possible 

 source of the material and reported some of his trials and failures 

 in a general paper (1733) . Phosphorus was usually prepared ^^ from 

 the waste products of man, but could be obtained from urine and 

 the excrement of other animals, such as " Lions, Tygers and Bears." 

 Hanckewitz wrote: 



My Curiosity led me likewise to Rats-Nests, and Mouse-Holes, and I 

 had Phosphorus thence. I then addressed myself to the feather'd Tribe, 



"John Evelyn, Diary and correspondence, ed. by Wtn. Bray, I, 2nd ed., London, 

 1819. 



^^ Often referred to merely as Ambrose Godfrey or Godfry. See Joseph Ince for 

 the life and character of Hanckewitz in the Pharmaceutical Journal 18: 126-130, 157- 

 162, 215-222, 1858. 



^^ Hanckewitz's secret method of preparing phosphorus was revealed in letters to 

 Johan Frederrick Henckel (1679-1744) , a councillor of mines in Freiberg. They 

 were published in 1794-1795. 



