220 ANNUAL OF SCIENTIFIC DISCOVERY. 



ARTIFICIAL DIAMONDS. 



It has been often suggested that in default of a " Carbon-Solvent," 

 electricity might possibly be brought to bear upon a carbonaceous 

 solution, so as to cause the carbon to be deposited pure in a crystal- 

 line form. Starting from this point ; a recent writer in the Dublin 

 University Magazine, makes the following suggestions. "Diamond 

 when fused by the heat in the open air, leaves a residue of pure car- 

 bon. Its attraction for solar light is so great that, after absorption, 

 it is sure to give it off when placed in a dark room. Its extreme 

 refrangibility shows.it to have for its base an oily substance. It is a 

 bad conductor of electricity, like all such substances. Suppose we 

 take_a portion of pure carbon (which is a powerful conductor of elec- 

 tricitv), produced bv burning to sooty residue a quantity of vesreta- 



t s ' \. * dJ * C* 



ble oil, say oil of origanum, which is the most inflammable ; then 

 place it in a close air-tight vessel constructed so as to admit a saturat- 

 ing supply of oxygen (which is a powerful conductor of electricity) ; 

 then bring to bear on this intensely oxygenized piece of carbon a 

 strong and constant electric current. While the latter produces vol- 

 atilization and intense molecular aggregations, it is very possible that 

 the union of oxygen with the carbon, under such conditions, would 

 result in the reconstruction of diamond substance, which would take 

 a crystallized form under the influence of the current ; while the oxy- 

 gen would restore to the diamond base the quality which it had lost. 

 The instrument should be exposed constantly in the light of the sun, 

 which exercises such influence on crystallization ; and as the harder 

 the crystals the longer the time it takes to form, the process of the 

 experiment would of necessity be extended over several or many 

 years." 



PERMEABILITY OF IROX. 



In the Annual of Scientific Discovery for 1864 (page 197), some 

 curious facts showing the porosity of platinum to hydrogen, 

 the results of experiments by M. Deville of Paris were given. 

 During the past year, the same author, in a paper presented to the 

 French Academy, announces the discovery of a similar property in 

 iron. The experiment, proving this, is detailed by him as follows. 



The great difficulty was to find a tube answering to the various con- 

 ditions required for the experiment. The best iron to be found in the 

 markets might still be open to some objection, since in point of fact 

 it is a mere sponge flattened by a hammer, like common platinum. 

 They succeeded at length in obtaining a tube of cast steel, contain- 

 ing so little carbon that it did not admit of being tempered. It was 

 in reality rather iron than steel, and so soft that it was drawn into a 

 tube without heating or soldering, though its sides were of a thick- 

 ness of from three to four millimeters. To the ends of this tube, two 

 other tubes of a much smaller diameter, and of copper, were soklerc'd 

 with silver ; the whole was then introduced into an open porcelain 

 tube, which was put into a furnace ; a glass tube, luted to one end, 

 established a communication with an apparatus generating hydrogen 

 completely deprived of atmospheric air ; while at the other end, 

 another glass tube, bent at right angles, dipped into a mercury bath, 



