424 Messrs. Daniel and Robert Cooper on the 



the microscopic examinations that there were no traces of ani- 

 mals, we resolved to repeat the experiments of Macartney and 

 Murray, as regards the non-disappearance of the phospho- 

 rescent light emitted from animals in the different gases. For 

 this purpose we prepared in well-stoppered phials the follow- 

 ing gases, viz. oxygen, hydrogen, nitrogen, chlorine, carbonic 

 acid, carbonic oxide, sulphuretted and phosphuretted hydro- 

 gen ; and into a phial filled with each of these gases we intro- 

 duced a portion of luminous muscle, tendon, or fascia for the 

 space of 4?0 minutes, and the following were the results of the 

 experiments : — 



No effect observed in Slight effect produced in Total extinction in 



Oxygen "l remained lu- Carbonic acid. Chlorine. 



Hydrogen l minoiis for Sulphuretted hy- 



Nitrogen J five days. drogen. 

 Carbonic oxide. 

 Phosphuretted Hydrogen. 



From the above experiments, we are compelled to disagree 

 with the conclusions of Macartney and Murray as regards the 

 non-disappearance of the phosphorescent light emitted from 

 animals when immersed in the different gases. By perusing 

 the above table, it will be observed that a total extinction of 

 the light takes place when immersed in chlorine and sulphu- 

 retted hydrogen : this took place within the space of two 

 minutes. 



Appeara?ice in vacuo. — On this point, we cannot coincide 

 with the opinions of Macartney and Murray, having intro- 

 duced an exceedingly luminous portion of flesh under the re- 

 ceiver of an air pump ; and upon exhausting the vessel, the 

 phosphorescence almost entirely disappeared, after having 

 been in vacuo for the space of 1 5 minutes ; but upon the re- 

 admission of the atmosphere, it immediately regained its for- 

 mer brilliancy, which is contrary to the opinions of the above 

 experimentalists. Upon removing the portion of flesh from 

 the phial containing carbonic acid, and placing it beneath 

 the receiver of the air pump, and on first exhausting, it ap- 

 peared to regain its luminosity in a slight degree; further 

 exhaustion however diminished it. Oxygen having been ad- 

 mitted in the place of air, it soon regained its original bril- 

 liancy ; this effect was in like manner produced by the admis- 

 sion of the atmosphere as before, and also by some of the dif- 

 ferent gases above-mentioned. 



Effect in condensed air. — From the result of the foregoing 

 experiment, viz. the diminution of the brilliancy upon with- 

 drawing the atmosphere, we were led to suppose that a con- 

 trary effect would be produced upon condensing the air : to 



