246 



HARDWICKKS SCIENCE-GOSSIP. 



of the district, and follows their course downwards. 

 It is not so obliging as to rush into a particular hole 

 that may be bored in a convenient part of a particular 

 London brewer's particular premises. Hence the 

 failure at Meux's brewery ; which so many regard as 

 proving the impossibility of supplying London from 

 below. Mere sinking of wells in the chalk is but a 

 foolish proceeding. Unless the sinking happens by 

 accident to strike a fissure, only a dribbling infiltration 

 through the sides of the well occurs. The proper 

 course of proceeding is to first ascertain the prevailing 

 direction of the fissures in the chalk, then to sink a 

 shaft into it, and from this to drive an adit or tunnel 

 at right angles to the course of the fissures. This has 

 been done at Brighton where, by means of the Gold- 

 stone tunnel, a continuous supply of 5J millions of 

 gallons are obtained daily ; two millions more than 

 the town can use. At Birmingham, where the water- 

 bearing rock is totally different, and therefore 

 demands different treatment, nine millions of gallons 

 are obtained daily from suburban wells : 3,000,000 

 from Aston ; 2,500,000 from Witton ; 250,000 from 

 King's Vale ; 2,000,000 from Perry; and 1,250,000 

 from Selly Oak. 



Telegraphic Invasion. — A remarkable illustra- 

 tion of the penetrating power of Science is supplied 

 by the fact that Seoul, the capital of Corea, is now in 

 telegraphic communication with Pekin and the rest 

 of the world. Six years ago any European who 

 ventured to visit Corea did so at the risk of his life, 

 all such intercourse with the outer barbaric world 

 being prohibited. Now, as "Nature" says, "a 

 merchant in London might telegraph direct to the 

 Hermit Kingdom." 



Hydrogenium. — The experiment of dipping a 

 knife blade into a solution of a salt of copper, and 

 thereby coating it with a film of metallic copper, is 

 very familiar, and is very instructive, because it is 

 a typical example of a widely extending chemical 

 law, that if we take two metals, varying materially in 

 their affinity for oxygen, and expose that which has 

 the stronger affinity for oxygen (the electro-positive 

 metal), to a solution of the electro-negative metal, or 

 that having the weaker affinity for oxygen, a pre- 

 cipitation of the latter in the metallic state from the 

 solution will take place. 



Hydrogen, although a gas under ordinary terres- 

 trial conditions, is a metal as regards its chemical 

 relations. Certain metals may be made to absorb or 

 occlude vast quantities of hydrogen gas ; this is 

 especially the case with palladium, which may 

 be made to take up more than 600 times its own 

 bulk of hydrogen, and become altered in its properties 

 thereby, the alteration corresponding to that which 

 occurs when one metal is alloyed by admixture 

 with another metal. The hydrogen becomes a solid 

 when thus occluded or alloyed, and this solid has 



been named hydrogenium, in accordance with the 

 established custom of using the termination um to 

 indicate the metallic condition. The theory of the 

 metallic character of this hydrogenium requires it to 

 be an intensely electro-positive metal, and therefore 

 that it shall precipitate the relatively electro-negative 

 metals from their solutions. Schwarzenbach and 

 Kritschowsky have recently proved this to be the 

 case. They saturate strips or wires of palladium 

 with hydrogen, then dip them into solutions of 

 different metals. The saturated palladium becomes 

 plated with the metal in solution, although previous 

 to its saturation no such precipitation or plating 

 occurs. This difference is attributed to the highly 

 electro-positive metal hydrogenium. 



The African Mediterranean. — One of the 

 grand projects of M. de Lesseps was to cut through a 

 strip of land, the Seuil de Gabes, or Khabs, or Cabes, 

 lat. 34 N., long. io° E., at the bottom of a bay or 

 gulf of that name (or rather all those names), and 

 thus let the sea into that depression of the Desert of 

 Sahara indicated by numerous lakes or "shotts," 

 such as Shott el Melah, Shott Melrhir, Alsibkar, Sec. 

 These lakes are fed by rivers which flow into them 

 and are lost. The evaporation from the surface of 

 the lake, and the sinking into the sands, is equal to 

 the supply of water brought down by the rivers. 

 Only thirty or forty miles of cutting through the 

 above-named strip is required to let the sea into the 

 salt lake of Alsibkar, and therefrom to spread it 

 throughout the whole region. This cutting, according 

 to a report presented about five years ago by Colonel 

 Roudaire to the Minister of Public Instruction, would 

 present no difficulty, the material being clay, marl, 

 sand, and chalk. 



The area of desert and salt lakes lying below the 

 level of the Mediterranean, and therefore included in 

 the flooding, was variously estimated from equal to 

 that of Ireland to something much more than that of 

 France. The area of Sahara altogether is about 

 thirty-five times that of England and Wales. The 

 desirability of converting a considerable portion of 

 this desert area into a lake is obvious. Not only 

 would an extensive coast-line be created, freely com- 

 municating with the outer world, but the climate 

 would be materially altered, and the deep sandy soil 

 resting on rock below would be watered by an under- 

 ground extension of the visible lake. 



Colonel Roudaire is dead, and in a communication 

 to the Academy of Sciences, at its sitting on the 2nd 

 of August last, M. de Lesseps states that the project 

 of creating an inland sea has been abandoned, and 

 that attention is now devoted to the Wed Melah 

 basin, which it is hoped may be restored to its former 

 fertility by sinking artesian wells. 



A New Vapour Engine. — M. Tellier has sub- 

 mitted to the Academy of Sciences an ingenious 



