Scientific Intell'igence. — Arts. 213 



what different, as taken at the Sandwich Islands and in the 

 Straits of Malacca. The former were globular and transparent, 

 with a yellowish point in the centre, the latter were rather oval 

 with a depression in the centre, so that they were somewhat 

 kidney-shaped ; they also were entirely yellowish. 



In all the animals which possess phosphorescence, the pro- 

 perty has appeared to us to depend upon a particular principle, 

 probably a secretion of these animals, which, however, differs 

 as to the manner in which it is scattered around. Some of them, 

 as the small phosphorescent Crustacea, can distinctly emit it in . 

 certain circumstances, especially when, by any cause, they are 

 irritated ; they then project true jets, regular fusees of phos- 

 phorescent matter, in such quantities as to form a luminous at- 

 mosphere in which they disappear. We have succeeded in col- 

 lecting a certain quantity of this matter upon the sides of a 

 vessel which contained a great number of these Crustacea. Others 

 of these animals did not appear to possess the power of emitting 

 this matter, and in them it was developed only in certain cir- 

 cumstances, as for example, when they struck against anybody, ^ 

 or when they moved, or when causes of irritation operated upon 

 them. In others again, as in the Cephalopoda, and in some 

 Pteropoda the phenomenon exhibited itself in a way that was 

 nearly quite passive. The phosphorescent matter contained 

 in their neucleus, or in other parts of their bodies, shone con- 

 stantly and uniformly so long as the animal was in the enjoy- 

 ment of life, and along with this disappeared the light they 

 shed abroad. Finally, in the yellowish corpuscules above de- 

 scribed, the phosphorescent matter also shines almost uniformly, 

 but if brought into contact with any reagent, their lustre is first 

 increased, and then insensibly vanishes away. The phospho- 

 rescent matter which we collected on the sides of the vase, was 

 yellowish, slightly viscous, and very soluble in the water, which 

 it rendered luminous at the moment it was projected by the 

 animal, — Comptes Ketidus, No. xv. 5 Avril, p. 458. 



ARTS. 



17. On the Composition of a new Indelible Ink. By Dr Traill. 

 — In a paper lately read before the Royal Society of Edin- 

 burgh, Dr Traill, after an account of many unsuccessful expe- 



