

214 Miscellanies. 



chapters on important subjects, and has posted up the science to the 

 date of his preface, April, 1833. 



The favorable opinion which, many years ago we formed and ex- 

 pressed respecting this work, is now, at last, fully confirmed by that 

 of the British scientific public ; namely, that Mr. BakewelVs Geology 

 is admitted to be the best elementary work for instruction on that 

 subject in the English language, and perhaps in any language. We 

 understand from direct and unquestionable sources, that this is now 

 admitted in the Universities of England and Scotland, as well as by 

 eminent* geologists in various parts of the United Kingdom. After 

 investigating geological subjects through many volumes of the various 

 existing treatises, we have usually returned to Mr. Bakewell for a 

 final judgment, and have been often forcibly struck with his judicious 

 summary of geological facts and opinions, and with the rare combina- 

 tion of copiousness, condensation and perspicuity, which his work 

 presents. 



18. Magnetism. — Dr. Locke, has within the last week, invented 

 and constructed a very delicate Thermo-electrical battery, intended to 

 show the electricity produced by animal heat. It is of the size of 

 three sixpences laid upon each other, that is, three-fourths of an 

 inch in diameter, and one tenth of an inch thick. This battery, 

 being attached to his galvanometer, and the end of the finger 

 applied to the top of it, the animal heat thus communicated to it, 

 caused a current of electricity, which turned the magnetic needle 

 90°. Independently of this little battery, the two following experi- 

 ments, have been made by the galvanometer. One fourth of a 

 grain of metallic antimony being interposed between two copper 

 wires, and the warmth of the finger appHed, the needle was deflect- 

 ed 22°. One of the copper wires being laid upon the other, without 

 the interposition of any other metal, and the warmth applied as above 

 the needle was deflected 6°. The same results were obtained by 

 substituting the warmth of the breath instead of that of the hand. 

 It may be proper to note that the temperature of the room in which 

 these experiments were made, was 65° Fahrenheit. 



It has thus been actually shown that the production and expenditure 

 of animal heat, are, constantly, attended by electrical and magneti- 

 cal currents. — Cincinnati Paper. 



* It has been used since 1815, in connexion with the geological lectures in Yale 

 College, and two editions of the work, each with an appendix, have been published 

 under the revision of the Professor in that department 



