Page:Experimental researches in chemistry and.djvu/230

1826.] I did from another journal, in which the experiment only was described), I turned to the original place, and there, though I found the experiment I had transferred, I also found another which I had previously made on the same subject, and which M. Bellani had quoted.

I very fully join in the regret which the 'Bulletin Universel' expresses, that scientific men do not know more perfectly what has been done, or what their companions are doing; but I am afraid the misfortune is inevitable. It is certainly impossible for any person who wishes to devote a portion of his time to chemical experiment, to read all the books and papers that are published in connexion with his pursuit; their number is immense, and the labour of winnowing out the few experimental and theoretical truths which in many of them are embarrassed by a very large proportion of uninteresting matter, of imagination, and of error, is'such, that most persons who try the experiment are quickly induced to make a selection in their reading, and thus inadvertently, at time, pass by what is really good.

On a peculiar Perspective Appearance of Aërial Light and Shade.

evening last month (Aug. 19, 1826), a curious aërial phenomenon was observed from the under cliff at the back of the Isle of Wight, just above Puck aster Cove. The sky was clear, the sun had just set to those who were standing where the appearance was observed, when several enormous rays of light and shade were remarked towards the E., N .E., and S.E., all radiating in strait lines from a spot rather south of east, and just upon the horizon. They were ten or twelve in number, did not join at the place from whence they appeared to originate, but seemed to emerge from an obscure portion of surface of a convex form 8° or 9° in horizontal extent, and about the third of that in height. The rays extended from 30° to 40° on the right and left from the centre, but were of less extent as they became more vertical. They diminished gradually in intensity at the extremities until they could be traced no further. The appearance slowly faded away, some of the rays disappearing