412 Dr. J. H. Pring's Observations a?id 



the admission of atmospheric air, at the time when the phos- 

 phorescent glow was beginning to grow faint. The result, 

 however, did not appear to be in any way influenced, nor was 

 the light in any degree resuscitated by this variation of the 

 experiment. 



Effects of Hydrogen. — Submitted to the action of this gas, 

 no very marked effect appeared to be produced upon the water. 

 On agitating a portion of it in a bottle containing this gas, 

 numerous specks of light, indicating the presence of the ani- 

 malculae, could be perceived for many successive nights ; but 

 the light appeared somewhat less vivid in its character than 

 that afforded with atmospheric air, or in the instance before 

 mentioned, in which pure nitrogen was employed. 



Effects of Atmospheric Air. — The influence of atmospheric 

 air is here introduced merely as affording a standard of com- 

 parison with the effects obtained from the employment of the 

 gases. A bottle of the luminous water, procured at the same 

 time as that used in the preceding experiments, retained its 

 luminosity a few days longer when subjected only to atmo- 

 spheric air, than under the eniployment of any of the above- 

 mentioned gases ; but the phosphorescence was only to be 

 observed on the occurrence of any agitation of the water. It 

 appears also that the luminous property is retained longer 

 when the vessel or bottle containing the water is kept closed 

 or corked, than when it is left entirely open and freely ex- 

 posed to the action of the air. 



3. Effects of the strong Mineral Acids. — For the purpose of 

 ascertaining whether the phosphorescence would be in any 

 way affected by the strong mineral acids, a small quantity of 

 water was placed in each of three glass vessels, and then a few 

 drops of acid were added to the water in each vessel, this 

 latter part of the experiment being of course conducted in the 

 dark. On letting fall a few drops of strong sw//;^M;7cac/W into 

 the water, the latter immediately emitted a bright light which 

 remained for the space of a minute or two, after which it 

 almost immediately disappeared. 



The effect of strong nitric acid appeared in no way to differ 

 from that produced by the sulphuric acid; but treated with 

 strong hydrochloric acid in the same manner, the increased 

 luminosity of the water was much less conspicuous than in 

 either of the former instances, and the darkness ensued almost 

 instantaneously. 



Effects qfJEther and Chloroform. — A few drops of aether 

 dropped into the sea-water in the dark appeared instantly to 

 deprive it of its luminous property, no degree of agitation to 

 which it was subjected being found capable of eliciting the 



