292 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



EXPERIMENTS ON AQUATIC ARTICULATES. 



Mr. Felix Plateau has lately published a second part of his 

 elaborate physical chemical inquiry into the aquatic articu- 

 lates, this paper being devoted to the resistance of these ani- 

 mals to asphyxia from submersion, to the action of cold and 

 the action of heat, and to a maximum temperature. The 

 general conclusions to which he arrives are, as regards resist- 

 ance to asphyxia from submersion, that the coleoptera resist 

 a complete submersion for a very long time, but that the 

 aquatic coleoptera and hemiptera, so far from being more 

 able to sustain a similar exposure, are really no way superior 

 to the terrestrial insects in this respect, and, in fact, some- 

 times succumb more quickly. The cause of this inferiority 

 would seem to be their greater activity while in the water, 

 and the consequent more rapid expenditure of the oxygen, 

 while the land insects use comparatively little effort. 



As regards the effect of cold, the aquatic insects appear 

 able to sustain an indefinite exposure in the water at the tem- 

 perature of freezing, but the time during Avhich they can re- 

 main in ice at that same temperature is exceedingly short. 

 The first cause of rapid death under these circumstances ai> 

 pears to be the deprivation of motion, and the consjequent 

 absorption of the bodily heat, without the possibility of res- 

 toration. 



As regards the action of heat, the author states that the 

 most elevated heat sustained without injury was between 

 33.5 C. and 46.2 C, consequently between very narrow lim- 

 its. These temperatures correspond to those of a consider- 

 able 23eriod of submersion in the water of the articulate an- 

 imals, whenever the salts of soluble gases do not exercise an 

 injurious influence. If the results Avhich have been fur- 

 nished by aquatic articulates are compared with those ob- 

 tained with animals of other groujos, it will be found that the 

 highest temj)erature of the aquatic animals, whether verte- 

 brate, articulate, or molluscan, does not exceed 4.5 C. Bull. 

 Acad. Roy ale cle JBelgique^ ix. and x., 172 and 320. 



A TAMED WASr. 



One of the novelties of the 1872 meeting of the British As- | 

 sociation was the exhibition by Sir John Lubbock of a social 



