182 Miscellaneous Intelligence. 



stance. Potassa dissolves the substance. It is not soluble in 

 bailing water, but becomes more consistent in it. From the 

 chemical character M. Macair concludes the substance to be 

 albumen principally, and the cause of the cessation of light to 

 be the coagulation of the albumen and its consequent opacity. 



The general conclusions are — 1. that a certain degree of heat 

 is necessary to the voluntary light of glow-worms. 2. That a 

 slightly increased heat increases the light, but much more heat 

 destroys it. 3. That all bodies capable of coagulating albumen 

 destroy the phosphorescence of this matter. 4. That the light 

 does not appear except in gases containing oxygen. 5. That 

 the pile excites it, but common electricity does not. 6. That 

 the luminous matter is principally albumen. 



15. Relation of a remarkable electrical Phenomenon. — The fol- 

 lowing relation is made by M. Allemand of Fleuvier Neuchatel, 

 to M. Pictet, and is published in the Bib. Univer., June 1821. 

 M. Allemand, on the 3d of May, about ten o'clock in the 

 evening, was caught in a violent storm of wind and rain. The 

 thunder becoming frequent and strong, he thought it proper 

 to close an umbrella he had with him, and hold the upper 

 metallic point in his hand, lest it should attract the light- 

 ning. The night, dark of itself, was made more so by the 

 great rain. Suddenly he perceived a light from above, and 

 looking upwards found the edge of his hat luminous. Sup- 

 posing at the moment the hat was on fire, he, without reflection, 

 passed his hand over the light to extinguish it. It however only 

 shone more strongly, a circumstance which caused some con- 

 fused ideas on the nature of the light. The hand being filled 

 with water from the hat, on shaking it, M. Allemand saw that 

 the interior of it shone as if it were a polished metal reflecting 

 a strong light. 



Being at this time near the farm of Chaux, about ten or twelve 

 minutes' walk from Fleurin, and fifteen or twenty from Motiers, 

 M. Allemand, considered for a moment what he had best do, and 

 concluded on continuing his progress. Having once filled his hand 

 with the electrified water with impunity, he ventured to repeat 

 the experiment, and did it fifteen or twenty times, endeavouring 

 to ascertain whether it had odour, or produced any decrepitation 

 or sound ; but nothing of this kind could be perceived, nothing 

 but the bright light which seemed like a brilliant varnish on the 

 hand. The light remained for an instant only. At a few hun- 

 dred paces farther on, the light on the hat still continuing, M. 

 Allemand was surprised by the appearance of another light less 

 bright than the former, on the smooth surface of the umbrella- 

 handle, at the place where generally a plate of metal is placed 

 for tiie name, but which plate had been removed from this um- 

 brella. At first the finger was passed over it to extinguish it, 



