'312 Miscellanies. 



ground-ice in the Old World ; those I have are not yet very com- 

 plete ; but I am already aware, that this phenomenon extends much 

 farther in a southerly direction in Siberia, than in Europe. The far- 

 ther we go east, the more southerly we find the limit of perpetual 

 ground-ice. Humboldt found at Bogoslovsk, in lat. 59° 45' N., at the 

 eastern foot of the Ural Mountains, small pieces of ice at the depth 

 of six feet in the summer. No permanent ice has been found in 

 Tobolsk in 58° N. ; but at Beresow, in 64° N., where Erman found the 

 temperature of the ground above 4"1°K.- ^^ the depth of 23 feet, we 

 learn from the observations of M. Belowski, that the lower districts 

 are never without ice in the ground, so that it is brobable that Bere- 

 sow is near the limit of perpetual ground-ice. Farther east, this 

 frozen soil extends much more to the southward, even to the shores 

 of the lake Baikal ; indeed, the whole of the southeastern angle of 

 Siberia has perpetual ground-ice. Captain Frehre states, that in 

 1836, he there found the ground frozen at some distance below the 

 surface, and that this frozen stratum was continued uninterruptedly 

 quite to the underlying rock, to a depth from 10 to 40 feet. But, as 

 he always found rock there, it would be difficult to say how thick the 

 layer of frozen mud would be in the lat. of 52°. It thawed on the 

 surface of the banks of the river, to a depth of from 2| feet to 6 feet, 

 and from 6 feet to 9 feet on the naked heights ; but, in the forests, 

 where the rays of the sun were intercepted, the thaw reached only 

 from f foot to 1 foot deep, if it be true, that there are places in for- 

 ests where the ground is never thawed one foot deep, it would demon- 

 strate how little is necessary for the ground to be thawed for trees to 

 grow on it. The development of the leaves and vegetation depends 

 less on the temperature of the soil than on that of the air in the 

 spring; it only requires that the ground should be so far thawed, that 

 the tree may be able to draw from it a sufficient quantity of moisture 

 for its growth."* — Edinburgh New Philosophical Journal, October, 

 1838. 



* Mr. De la Beche remarked, that, considered geologically, this paper of Prof. 

 Baer, was an important one. It showed that the temperature of those regions had 

 changed since the deposit of the detrital matter (for that was the character of the 

 frozen ground) inasmuch as, under the condition of a perpetually frozen surface, 

 no such deposits could take place. 



