INDUSTRIAL PROGRESS DURING THE YEAR 1873. Ixxxv 



the past year an interesting series of articles by Claude Ber- 

 nard have appeared in Mevue des Cows Sclentifique^ on the 

 phenomena of life common to animals and vegetables. He 

 contends that " a fundamental conception dominates general 

 physiology that of the unity of nutrition in all living be- 

 inscs." 



M. Felix Plateau continues his interesting physico-chemi- 

 cal investigations upon the aquatic articulates, particularly 

 the insects. Having previously experimented on the causes 

 of the death of the fresh-water Articulata in sea-water, and of 

 the marine Articulata in fresh water, in the second part of his 

 investigations he takes up three other interesting questions : 

 First, he details certain experiments on the time during 

 Avhich the aquatic Articulata can remain in the water with- 

 out coming to the surface to breathe. He finds that terres- 

 trial Coleoptera (beetles) resist complete submersion during a 

 very long time, i. e., for three to four days. It seems that 

 swimming aquatic Coleoptera and Hemiptera, far from pre- 

 senting a greater resistance to asphyxia by submersion, are 

 no better endowed in this respect than terrestrial insects, and 

 even perish in most cases much more rapidly. The cause of 

 this unexpected inferiority of the aquatic insects seems to 

 consist exclusively in their greater activity in the water, and, 

 consequently, in a more rapid expenditure of oxygen. Sec- 

 ondly, he finds that aquatic Articulata can exist for an in- 

 definite period in water, kept by means of melting ice at a 

 temperature of 32 Fahr. But if the same insects are placed 

 in -ice at 32, they die within less than half an hour. The 

 primary cause of rapid death when Articulata are fixed in 

 ice seems to be the absolute privation of movement, and the 

 consequent absorption of the corporeal heat, without any 

 -possible restitution. Thirdly, he has endeavored to ascertain 

 the highest temperature which our fresh-water insects, Arach- 

 nida and Crustacea, can endure in other words, what is the 

 temperature of the hottest water in which they can live. 

 He finds that it is between 92 and 115 Fahr. These 

 temperatures, he remarks, correspond with those of a cer- 

 tain number of known thermal springs, in the waters of 

 which we may meet with articulate animals, wherever the 

 salts or gases in solution have no injurious action upon them. 

 Finally, he finds that the highest temperature that aquatic 



