1856.] Inieresttng Pldlosoiyldcal Questions. 205 



packed in moss ? If the latter, it is no new discovery. Such protection, 

 or packing to the roots, acts as the earth does, if permitted to remain 

 undisturbed, until by the natural process of temperature, the frost is 

 drawn out. A tree, however, with its roots exposed to hard freezing, 

 without protection, will as assuredly be destroyed as if exposed to a hot sun 

 for any considerable time. There is an appropriateness in all organized 

 existence, which we may not transcend with impunity, and this is no 

 ■where more apparent than in vegetable life. 



Very respectfully yours, 



A. H. Ernst. 

 Spring Garden, March 11, 1S5G. 



INTERESTING PHILOSOPHICAL QUESTIONS. 



Some curious questions in the obscurer branches of science have been 

 recently debated at the London Royal Institution. Dr. Tyndall has 

 been examining the subject of tones emitted by masses of heated metal 

 while cooling. He proved by repeated experiments the incorrectness of 

 the explanation hitherto received, but was still unable to assign the 

 phenomena to their true cause. Another was on some most extraordi- 

 nary effects of motion, which the Eev. Badin Powell, though he interested 

 his auditors in the experiments, could not satisfactorily explain. One 

 of the effects is this : Let a beam, free to turn in all directions, be bal- 

 anced horizontally on the top of a standard ; then put a small wheel on 

 one end, cause it to rotate rapidly, and the beam will still retain its 

 horizontal position, notwithstanding the weight of the wheel. It is as 

 though motion nullified gravity ; but as some of the most ingenious 

 English philosophers are examining into the phenomenon, it is hoped an 

 explanation may ere loDg be found. Another interesting subject is that 

 brought forward by Piofessor Edward Forbes, who has started an inquiry 

 as to the depth of primeval oceans, and who believes it possible to throw 

 light upon it by a study of the color of fossil shells. The shallower the 

 water the more intense the color, is the experience gained by d-edging 

 in the seas of the present period ; and, reasoning from analogy, we may 

 infer the same law prevailed in earlier periods. Ehrenberg, too, con- 

 tributes more to our knowledge of ocean life ; he has examined specimens 

 of mud brought up from the depth of six thousand fathoms, and finds 

 them to contain living infusoria. 



