1^6 Obfervatlons on the 



5. When the fifiures are filled with matter different from 

 the body of the mountain, that matter is called a vein. 



6. Laftly, one mud examine, in both fides of the fame 

 fiflure, whether the firata correfpond at the fame height, or 

 whether the correfponding ftrata are lower on one fide than 

 on the other. The firft cafe indicates that the fiflure has 

 been produced by mere burfting afunder ; and the fecond 

 proves, befides, a finking down of the earth *. 



[To be continued.] 



VII. Obfcrvations on the Winter Sleep of Animals and 

 Plants. By Profejfor Fa brici us. From Magazin fur 

 das neuefte aus dcr Phyfik. Vol. IX. 



T 



HE fo called winter flecp is a very lingular property of 

 animals and plants ; and though it occurs daily before our 

 eyes, we are not able to explain the phenomena with which 

 it is attended. In cold countries many animals, on the ap- 

 proach of winter, retire to their fubterranean abodes, in 

 which they bury themfelves under the fnow, where they re- 

 main five or fix months without nourifhment or motion ; 

 nay, armoft without circulation of their blood, which flows 

 only fluggtfhly and in the wideft vefl'els. Their perfpiration 

 is almofl imperceptible : but ftill they lofe l'omething by it j 

 as they enter their winter quarters in very good condition, 

 and are exceedingly thin when they return from them. 



Some animals enjoy their winter fleep under the earth, 

 and others concealed below the fnow; fome for the fame 

 purpofe creep into the holes of rocks, and others below 

 Hones or the bark of trees. Some kinds, fuch as fwallows 

 and frogs, can pais the winter in marines under the water. 

 In this ftate many of thofe expofed to the feyerity of the 



• To obferve whether this finking down has not always taken place o» 

 that fide which looks towards the fiat country. C. 



9 . »pe» 



