LITERARY NOTICES. 



559 



thing on that must depend upon them. The 

 cause of truth may be injured by over- 

 haste ; it can only be benefited by delibera- 

 tion and careful examination. 



Local Institutions in Virginia. By Ed- 

 ward Ingle. Baltimore : N. Murray. 

 Pp. 127. Price, 75 cents. 



This essay, constituting numbers two 

 and three of the third series of the " Johns 

 Hopkins University Studies in Historical 

 and Political Science," is not inferior in in- 

 terest and importance to any of the num- 

 bers of either series that has preceded it. 

 Virginia was a " mother of commonwealths," 

 and the results of her development and her 

 policy were impressed, in one shape or an- 

 other, and to a greater or less extent, in 

 Kentucky and the States that were formed 

 out of the Northwest Territory. The pur- 

 pose of Mr. Ingle's study is to ascertain 

 from what these results were developed, 

 and hew. In pursuing it, he considers the 

 character of the country and its settlers 

 (" Virginia and the Virginians ") " The Land- 

 Tenure of the Colony," " The Organization of 

 the Hundred," " The Fortunes of the English 

 Parish in America," " The County System of 

 Colonial Virginia," and " The Town." Un- 

 der the last head, the curious fact is devel- 

 oped that towns which in other States ap- 

 pear variously as the original form of set- 

 tlement, of spontaneons growth, or as the 

 ready creatures of speculation, were not nat- 

 ural to Virginia ; and that the formation of 

 them was the object of several laborious 

 efforts, prosecuted against a chronic indis- 

 position of the people to settle in them or 

 to favor them at all. 



Geology of the Comstock Lode and the 

 Washoe District. By George F. Beck- 

 er. Pp. 422, with Plates and an Atlas. 

 Price, 111. Comstock Mining and Min- 

 ers. By Eliot Lord. Pp. 451. 



The surveys upon which Mr. Becker's 

 report is based were conducted by him as 

 aid to Mr. Clarence King, and chiefly in the 

 lower parts of the lode. Mr. King has al- 

 ready made the upper part familiar to ge- 

 ologists. In his work Mr. Becker had the 

 assistance of Dr. Carl Barus, physicist, who 

 made researches in the electrical activity of 

 ore-bodies and in kaolinization, the results 

 of which are incorporated here. In the re- 



port, the general account of the Comstock 

 mines and the review of previous investiga- 

 tions of the lode are followed by chapters 

 on the " Lithology of the Washoe District," 

 with detailed descriptions of sections of the 

 rocks prepared for microscopic examination ; 

 on the structural results of faulting, the oc- 

 currence and succession of the rocks, the 

 heat-phenomena of the lode, and Dr. Barus's 

 papers on " Kaolinization and on the Electri- 

 cal Activity of Ore-Bodies." The relations 

 of the minerals and the changes they have 

 undergone are discussed very fully in the 

 chapters on "Lithology" and "Chemistry," 

 and the character and causes of the heat- 

 phenomena of the lode, with the various 

 theories that have been proposed to account 

 for them, as fully in the chapter on that sub- 

 ject. These heat-phenomena are one of the 

 most famous peculiarities of the Comstock 

 Lode, and distinguish it from all other mines 

 and excavations under the earth's surface. 

 The unusually high temperature was mani- 

 fested in the upper levels, and has increased 

 with the depth. The present workings are 

 intensely hot ; and, during the winter of 

 1880-'81, the water in one of the levels 

 reached a temperature of 170 Fahr., at 

 which food may be cooked, and the human 

 epidermis is destroyed. The rapidity of the 

 ventilation required to reduce the tempera- 

 ture of the air is something unknown else- 

 where, yet deaths in ventilated workings from 

 heat alone are common, and there are drifts 

 which without ventilation the most seasoned 

 miner can not enter for a moment. The 

 origin of this high temperature has been at- 

 tributed to the kaolinization of the feldspar 

 in the country rock and to residual volcanic 

 activity. No positive evidence is adduced 

 that it is due to kaolinization, and the results 

 of Dr. Barus's experiments on the thermal 

 effect of the action of aqueous vapor on feld- 

 spathic rocks, so far as they have been car- 

 ried out, were wholly negative. No heating 

 effect due to this cause could be detected with 

 an apparatus delicate enough to register a 

 change of temperature of one thousandth of 

 a degree C. On the other hand, there is 

 much geological evidence pointing to a deep- 

 seated source of heat, probably of volcanic 

 origin, or solfataric. The floods of waters 

 which have been met in the mines can not 

 be accounted for by any hypothesis connect- 



