68o THE POPULAR SCIENCE MONTHLY. 



think not. Tiie conditions necessary to the formation of canons are 

 exceptional in the world's history. 



We have looked back unnumbered centuries into the past, and 

 seen the time when the schists in the depths of the Grand Canon were 

 first formed as sedimentary beds beneath the sea ; we have seen this 

 long period followed by another of dry land so long that even hun- 

 dreds, or perhaps thousands, of feet of beds were washed away by 

 the rains ; and, in turn, followed by another period of ocean triumph, 

 so long, that at least 10,000 feet of sandstones were accumulated as 

 sediments, when the sea yielded dominion to the powers of the air, 

 and the region was again dry land. But aerial forces carried away 

 the 10,000 feet of rocks, by a process slow yet unrelenting, until the 

 sea again rolled over the land, and more than 10,000 feet of rocky 

 beds were built over the bottom of the sea ; and then again the rest- 

 less sea retired, and the golden, purple, and black hosts of heaven 

 made missiles of their own misty bodies balls of hail, flakes of snow, 

 and drops of rain and when the storm of war came, the new rocks 

 fled to the sea. Now we have caiion-gorges and deeply-eroded val- 

 leys, and still the hills are disappearing, the mountains themselves are 

 wasting away, the plateaus are dissolving, and the geologist, in the 

 light of the past history of the earth, makes prophecy of a time when 

 this desolate land of Titanic rocks shall become a valley of many 

 valleys, and yet again the sea will invade the land, and the coral 

 animals build their reefs in the infinitesimal laboratories of life, and 

 lowly beings shall weave nacre-lined shrouds for themselves, and the 

 shrouds shall remain entombed in the bottom of the sea, when the 

 people shall be changed, by the chemistry of life, into new forms ; 

 monsters of the deep shall live and die, and their bones be buried in 

 the coral sands. Then other mountains and other hills shall be washed 

 into the Colorado Sea, and coral-reefs, and shales, and bones, and dis- 

 integrated mountains, shall be made into beds of rock, for a new land, 

 where new rivers shall flow. 



Thus ever the land and sea are changing; old lands are buried, 

 and new lands are born, and with advancing periods new complexities 

 of rock are found ; new complexities of life evolved. 



A ]S"EW ANTISEPTIC. 



CHEMISTS have long been familiar with the substance known as 

 salicylic acid, and in the text-books most of its properties are 

 described, as also the various modes of preparing it. Its most valu- 

 able property, however, namely, its action as an anti-ferment and anti- 

 septic, was discovered only about a year ago, by Prof. Kolbe, of the 



