396 TRA>'SACTIOXS OF THE AMERICAN INSTITUTE. 



state and in compounds. The law of Dulong and Petit — that the specific 

 heat of elements is directly proportional . to their atomic weight — is not 

 nniversally applicable. 



Iodide of Silver. 



That modification of Iodide of Silver, which is insensitive to the action 

 of light, has been rendered sensitive by M. Kaiser of Leipzig, who submits 

 the iodide to the action of the vapor of benzol, which develops ozone in 

 the air. Ozonized air produced by electricity has the same action. 



The TVoethltttpe. 



This new photographic process recently invented in Germany, by 

 Worthly, is exciting great interest. It substitutes a double salt of uranium 

 for the nitrate of silver, and collodion for albumen in the preparation of 

 the paper on which the picture is taken. The paper is so affected that the 

 action or light penetrates entirely through it, and the picture is therefore 

 unfading. Cheapness, precision, permanence, and ease in working, are the 

 chief advantages of the new process. 



The Emew. 



Mr. W. Bennett has been making experiments at Surrey in breeding this 

 species of large bird which cannot fly. The number of eggs laid by the 

 female is large, but she takes no part in the incubation This duty is per- 

 formed by the male who finds the eggs in various sheltered places and 

 collects them. The normal period of incubation is about sixty days. 



The Great Auk. 



Mr. A. Xewton has secured from Penguin Island, 170 miles north of St. 

 Johns, Newfoundland, a natural rmimmy of this remarkable bird, which 

 has excited as much interest among geologists as the Do/io. Although 

 numerous .skins are in the museums of natural history, this skeleton, now 

 in the hands of Prof. Owen, with one other, are the only specimens now in 

 Europe. 



Light of the Cucuyos. 



M. Pasteur, in a communication to the Paris Academy of Science, states 

 that the Cucuyos, an insect having wings protected by a shell like the 

 beetle, is very common in Mexico. It emits a phosphorescent light so 

 intense as to enable a person to read by it at night. Its light, like that of 

 the glow-worm, gives through the spectroscope merely a beautiful continu- 

 ous spectrum, but without lines. Mexican ladies keep these insects by 

 feeding them on sugar and giving them a bath once or twice a day. They 

 are used as ornaments at evening parties. 



Ero3ion of Lead by Insects. 



Tne Chemical Kev;8 cites a number of cases. In 1858 Marshal Vaillant 

 exhibited to the French Academy leaden bullets brought back from the 

 Crimea, in some of which the larvae of insects had excavated circular pa.s- 

 sages three or four millimeters in diameter. The insects were from the 

 wood of the cases in which the bullets were packed. In 1844 cartridges 



