458 C. H. Merinam — Fauna of Great Smoky Mountains. 



When the current density The per centage of calculated 



per sq. cm. of either elec- gas actually liberated was : 



trode was : 



20-9 52 



59-3 ...... 95*3 



These results, corroborated by several previous series, go to 

 show that for a rate of alternation of 200 per second and cur- 

 rents of between 01 and 0'35 amperes the quantity of gas 

 generated by an alternating current in a voltameter is approxi- 

 mately equal to that generated by an equal continuous current 

 when the mean current density at the surface of the electrode 

 is above 50 amperes per sq. cm. of each ; that below that den- 

 sity the quantity of gas developed rapidly diminishes, and that 

 below 1 ampere per sq. cm. soon disappears. 



Also that the resistance of a voltameter with very small 

 plates traversed by an alternating current is much less than 

 that it would offer to an equal continuous current. Were this 

 not the case, the resistance of a voltameter for alternating cur- 

 rent measurements might for many purposes prove prohibi- 

 tively great. 



Art. XLYII. — Remarks on the Fauna of the Great Smoky 

 Mountains / with Description of a new species of Red- 

 hacked Mouse {Fvotomys Carolinensis) ; by Dr. C. Hart 

 Merriam. 



The fauna of the higher portions of the southern Allegha- 

 nies remained almost unknown until 1870, when Prof. E. D. 

 Cope published a paper on the subject.* His bird notes were 

 made so late in the season (in August and September) as to in- 

 clude the beginning of the fall migration and hence are without 

 value so far as concerns the faunal position of the region. 

 Among mammals, he recorded the Red Squirrel and Canada 

 Lynx as inhabiting the higher mountains. A single species of 

 Salamander, the northern Desmognathus och?*oj?hcBus, was found 

 on the high peaks of the Black Mountains. 



The botany of the region received considerable attention, but 

 sixteen years passed after the appearance of Prof. Cope's paper 

 before anything of importance was contributed to our knowl- 

 edge of its- vertebrate fauna. In 1886 Mr. William Brewster 

 published the results of a very brief visit, made at the begin- 

 ning of the breeding season of birds, to the mountains of west- 

 ern North Carolina (The Auk, iii, 1886, 94-112 ; 173-179). 



* Observations on the Fauna of the Southern Alleghanies. Am. Nat. iv, 

 1870, pp. 392-402. 



