45 > On the light from organifed Bodies. 



Exper. 9. Two drams of purified or refined fugar being diffolved in two ounces of water, 

 and mixed with the fliining matter of a herring, the fluid acquired a great degree of 

 lu^idnefs. Tlae fame effeft took place when the experiment was made with foft brown 

 fugar. 



N. B. It is almoft needlefs to mention, that the degree of illumination in thefe liquids 

 mud depend upon the quantity of lucific matter applied ; but, in general, as much as can 

 be fcraped ofF by the blunt point of a moderately-fized knife, at a few times, will be 

 fufhcient, being aflifted by a ftrong agitation of the containing phial. 



OBSERVATION. 



Thefe experiments enable us to take light and diffafe it through water, fo as to render 

 the whole liquid moft brilliantly luminous, or, in other words, to impregnate water with 

 light. By thefe means, the light is fo extended in its furface, and combined in fuch 

 a manner, as to become exceedingly convenient and ufeful for various other ex- 

 periments. 



SECTION V. 



When fpontaueous Light is extitigui/hed by fome Bodies or Subjlances, it is not lo/l, but may 

 be again revived in its former Splendour, and that by the mojl fimple Means. 



EXPERIMENTS. 



Exper. I. On the ift of June, 1795, the following experiments were made, to know 

 what was the beft proportion of Epfom fait to water, in order to produce the moft 

 luminous liquid. Some fliining matter was taken from a mackerel, and mixed with a 

 folution of feven drams of the fait in one ounce of water; and its light was immediately 

 extinguiflied. The fame efFe£l enfued, but in a lefs degree, with a folution of fix, and 

 one of five drams. In a folution of two drams, in the fame quantity of water, the liquid 

 was luminous ; but much more fo when only one dram of fait was ufed. Obferving the 

 extindion of light to take place, as above, in the more faturated folutions, while the 

 diluted folutions were luminous, it occurred to me to endeavour to difcover what became 

 of the extinguiflied light, in the former cafe, and whether it might not be revived by 

 dilution. For this purpofe, I took the folution of feven drams of fait in one ounce of 

 water, in which the lucid matter from a mackerel had been extinguifhed, and diluted it 

 with fix ounces of cold pump water ; when, to my great aftonifliment, light in a moment 

 burft out of darknefs, and the whole liquid became beautifully luminous ! This revived 

 light remained above 48 hours, that is, as long as other light in general does, which has 

 never been extinguifhed. Hence, it had loft nothing of its vivid luminous powers by its 

 extinction. 



Exper. 



