P OP ULAR MIS CELLA.L Y. 



765 



he be disheartened by the temporary fail- 

 ure of his experiments, nor at the slowness 

 of his processes. " Buusen was obliged to 

 evaporate forty-four tons of the waters of 

 tlie Diircheim springs in order to obtain two 

 hundred grains of his new metal, caesium. 

 It took Betthelot several months to form, 

 by a series of synthetical operations, an ap- 

 preciable quantity of alcohol from water 

 and carbon, derived from carbonate of 

 baryta. Many years ago, in the laboratory 

 of Wurtz, a poor student was carrying from 

 one room to another a glass globe which 

 contained the product of a month's contin- 

 uous labor, when the bottom of the globe 

 fell out, and the contents were lost. Noth- 

 ing daunted, he recommenced his month's 

 work, and brought his research to a suc- 

 cessful issue. Above all things, the chemist 

 must be true. He must not allow his wishes 

 to bias his judgment or prevent him from 

 seeing his researches in their true light. He 

 must not be satisfied that his results appear 

 true, but he must believe them to be true ; 

 and, having faithfully performed his experi- 

 ments, he must record them faithfully. He 

 may often be obliged to chronicle his own 

 failures and describe operations that tell 

 against his own theories, but this hard test 

 of his truthfulness he must not shrink 

 from." 



A Now Form of Galvanic Cell. When 

 rods of zinc and copper are placed in mer- 

 cury, and connected with an electrometer, 

 no change is observed ; and, whether the 

 zinc and copper are in contact outside the 

 mercury or not, the amalgamation of the 

 zinc appears to proceed at the same rate. 

 According to a communication to the Lon- 

 don Royal Society, from Profs. Ayrtou and 

 Perry, of the Tokio Engineering College, the 

 impurities and great conductivity of the zinc, 

 with the great liquidity of the amalgam, and 

 the close proximity of foreign particles to 

 pure metal, cause the amalgamation to be 

 produced by local action alone, so that the 

 supply of available chemical energy for the 

 production of a current from the zinc to the 

 copper is exceedingly small: at low tem- 

 peratures, when the amalgam loses its liquid- 

 ity, such an arrangement would, the authors 

 conjectured, become a simple voltaic cell. 

 To test this they substituted, for zinc, mag- 



nesium, whose amalgam is nearly solid at 

 ordinary temperatures. Strips of platinum 

 and magnesium, metallically attached to the 

 electrodes of the electrometer, were dropped 

 into mercury which had been washed with 

 distilled water and then well dried. There 

 was a sudden large deflection, afterward 

 fluctuating very much, but keeping always 

 on the same side of zero. On successive 

 reversals of the electrometer key, the de- 

 flections to the right and left of zero were 

 found to be nearly equal to one another. 

 To determine the electro-motive force of the 

 arrangement, strips of platinum and mag- 

 nesium, scraped very clean, were dipped into 

 pure mercury. The maximum electromotric 

 force obtained was 1.56 volts equal to one 

 and a half time the electromotrive force of 

 a Daniell cell. The authors remark that, 

 by mechanical or other means, or by using 

 another metal than magnesium, it may be 

 possible to give constancy to this arrange- 

 ment ; and as its internal resistance is ex- 

 tremely small, the cell may be of great 

 practical use for the production of power 

 ful currents. As an amalgam may be easily 

 separated into its components by distilla- 

 tion, such a cell might be kept in action 

 ' for an indefinite time. 



An Interesting Geological Question. 



Though the Triassic rocks of New Jersey 

 and the Connecticut Valley are commonly 

 regarded by geologists as intrusive igneous 

 rocks, the direct proof of their intrusive na- 

 ture is not readily accessible. Indeed, some 

 geologists have supposed that, so far from 

 being intrusive, they were formed contem- 

 poraneously with the shales and sandstones 

 amid which they occur, as a bed of igneous 

 rock at the bottom of a shallow sea in which 

 the stratified rocks were being deposited. 

 But Mr. I. C. Russell shows, in the Ameri- 

 can Journal of Science, that these trap-rocks 

 were forced out in a fused state among the 

 sedimentary strata after the consolidation 

 of the latter, and hence that they are more 

 recent than either the rocks above or below 

 them. The evidence of this he finds in a ra- 

 vine on the western slope of the First New- 

 ark Mountain, directly west of Westfield, 

 New Jersey. Here the trap-rock which ap- 

 pears in the bed of a little brook presents 

 its usual characteristics of a hard, bluish, 



