HARDVVICKE'S SCIENCE-GOSSIP. 



The experiments of Du Bois Reymond show that 

 this resistance to conduction and its irreciprocity are 

 vital properties, as the dead structure of the electrical 

 organs conducts equally in both directions, and more 

 readily than a saline solution. 



The irreciprocity of conduction of the electric 

 organ of the torpedo is limited to currents of brief 

 duration, like those which result from making and 

 breaking contact in induction coils. It does not 

 occur to continuous direct battery currents. This 

 special adaptation to the requirements of the animal 

 is very interesting. Its own electrical efforts are 

 spasmodic. It supplies no continuous current. 



Water and Chemical Combination. — A 

 curious chemical fact has been recently demonstrated 

 by Dixon, viz. that mixtures of perfectly dry carbonic 

 oxide and perfectly dry oxygen are not exploded by 

 the passage of electric sparks through them, and it 

 appears probable that even a mixture of hydrogen 

 and oxygen is similarly inexplosive without the help 

 of a minute quantity of already combined water 

 vapour. The cause of this is still under discussion. 

 Traube connects it with the formation of peroxide of 

 hydrogen. However this may be, it is a curious 

 paradox that water which we use for the extinction 

 of common combustion, i.e. the union of carbon with 

 oxygen to form carbonic acid and the union of 

 hydrogen with oxygen, should be necessary to effect 

 this same combustion. It presents us with a chemical 

 instance of "similia similibus curantur," but in 

 this case the conflagration mischief is promoted by 

 the infinitesimal dose, and the cure effected by very 

 large doses of the same. 



Coal in the Arctic Regions. — Lieut. Greely 

 has found more coal in the bitterest frozen regions 

 within the Arctic circle, besides the remarkable seam 

 of Grinnell Land. Also a fossil forest near Cape 

 Baird in i° 30' N. latitude. The coal seams are 

 displayed in outcrop or section at the surface, and 

 thus are visible to the mere passer by without any of 

 the laborious search by boring and sinking which are 

 necessary for the proving of our coal at home. If 

 the hidden or covered coal is proportionally abundant, 

 Greenland must be a remarkably rich coal bearing 

 region. 



These facts suggest much speculation : the first that 

 thrusts itself most obviously forth, being that of a 

 shifting of the earth's axis within the earth itself, but 

 this is demolished without mercy by fundamental 

 dynamic law. The earth is a spheroid of rotation 

 and such a spheroid can only rotate freely on its 

 shortest axis. In order to shift the present axis we 

 must either build up a mountain 13I miles high at 

 each pole, each with a base extending about halfway to 

 the equator, or shave off a corresponding thickness 

 from the equator and on each side of it, or do half of 

 one and half of the other, in order to make the earth a 



sphere that shall turn indifferently on any axis within 

 itself. Even after this, a further force to shift to 

 establish direction of rotation would be required. 



The other idea that has been much discussed, viz. 

 a tilting of the whole globe as it continues to turn on 

 its present axis so as to present it differently to the 

 sun, presents very serious dynamical difficulties which 

 those who best understand the subject the most fully 

 appreciate. 



For my own part, I am not by any means satisfied 

 with the prevailing notion which demands a sub- 

 tropical climate for the formation of coal. In 

 " Science in Short Chapters " (pp. 90 to 93), I have 

 described the deposition of coal that is in actual 

 present progress in the Nordals and other Norwegian 

 fjords within four degrees of the Arctic circle, and I 

 have no doubt that similar deposits may be found 

 much further north, and therefore no very violent 

 alteration of climate is demanded to explain the 

 Greenland coal. We require to know more about 

 the kind of fossil vegetation with which it is associated, 

 before assuming that the coal itself was formed by 

 vegetation demanding a climate very different from 

 that which supports the existing Siberian and 

 Norwegian forests. 



Natural Gas Fuel. — The iron trade of the 

 United States is in a state of considerable excitement, 

 on account of the successful application of natural 

 gas to smelting and forging. " The Petroleum Age " 

 tells us that " this invention seems likely to revolu- 

 tionize the smelting of iron, steel, and glass in the 

 United States." Doubtless it will if the supply 

 continues for any considerable length of time, but 

 this is very questionable, as the natural gas is but the 

 more volatile portion of the petroleum below, and 

 constitutes only a small percentage of it. When the 

 explorers first " strike ile " in a particular pocket or 

 subterranean cavity, the vapour previously confined 

 there usually rushes up the bore-hole with great 

 violence ; tales are told of boring tools being thrown 

 up in the air, &c. &c. These may be accepted with 

 as many grains of salt as may suit the reader's taste. 

 Certainly the force of uprush is great, but it rapidly 

 diminishes, and the spouting well becomes next a 

 flowing well, and then a well that must be pumped 

 in order to obtain the liquid petroleum. There are 

 issues of natural gas which have continued for ages, 

 but these are small in volume, sufficient for the altars 

 of fire worshippers, but not for forging and rolling 

 thousands of tons of rails, plates, &c. 



The gas is used by first mixing it with the quantity 

 of air which is necessary for its complete combustion, 

 and then throwing the barely visible flame thus 

 obtained directly upon the |metal. Such a flame is 

 not like that of a candle or lamp or of ordinary gas 

 burners, all of which are hollow shells of flame 

 enclosing gas that is being burned only on the outside. 

 The flames used in the furnaces are what are called 



