on the Light emitted from various Bodies. 173 



ness. The same effect took place when the experiment was 

 made with soft brown sugar. 



N. B. It is almost needless to mention, that the degree of 

 illumination in these liquids must depend upon the quantity of 

 lucific matter applied; but, in general, as much as can be 

 scraped off by the blunt point of a moderately-sized knife, at 

 a few times, will be sufficient, being assisted by a strong agi- 

 tation of the containing phial. 



OBSERVATION. 



These experiments enable us to take light and diffuse it 

 through water, so as to render the whole liquid most brilliantly 

 luminous, or, in other words, to impregnate water with light. 

 By these means, the light is so extended in its surface, and 

 combined in such a manner, as to become exceedingly conve- 

 nient and useful for various other experiments. 



SECTION V. 



When spontaneous Light is extinguished by some Bodies or Sub- 

 stances, it is not lost, but may be again revived in its former 

 Splendour, and that by the most simple Means. 



EXPERIMENTS. 



Exper. 1. On the 1st of June, 1795, the following expe- 

 riments were made, to know what was the best proportion of 

 Epsom salt to water, in order to produce the most luminous 

 liquid. Some shining matter was taken from a mackerel, and 

 mixed with a solution of seven drams of the salt in one ounce of 

 water ; and its light was immediately extinguished. The same 

 effect ensued, but in a less degree, with a solution of six, and 



