SCIENCE. 



Fic. 0. 



"With the spark," says M. Plante, " the distribution 

 of negative electricity presents a curious crab-shaped 

 appearance (Fig. 6.) With the aigrette, the electric 

 movement around this same negative pole gives us the 

 no less bizarre form of a polypus whose tentacles extend 

 towards the positive pole, but do not reach it." (Fig. 5.) 



From these results and other experiments quoted by 

 M. Plante, he concludes that a blending of the two elec- 

 tricities may exist at each pole. This would infer that 

 with electric currents ot sufficient tension to obtain a 

 continued series of discharges of static electricity, we 

 could have a complete decomposition of the water at 

 each pole and consequently a mixture of hydrogen and 

 oxygen. 



Pushing the study of these sparks still further, we 

 find that the movement proceeding from the positive 

 pole, externally, envelopes the negative electric movement 

 like a bundle of curved sky-rockets. However, we often 

 see at the "same time an inward flux of positive electricity 

 around the line of the spark between the positive current 

 enveloping the exterior, and between both, the negative 

 electric current which appears as though inhaled by the 

 positive pole. This led M. Plante to suppose that the 

 negative electricity, or else the ponderable matter which 

 it carries with it, moves in an annular space furnished by 

 the electrified matter proceeding from the positive pole. 

 According to him, it would follow that the aspiratory or 

 ascendant effects of the water obtained by electric cur- 

 rents of high tension might explain the ascension of 

 water in a cloudy form as seen in water-spouts. 



In a forthcoming article we will study other phenomena 

 no less remarkable, which have been revealed by M. 

 Plante's rheostatic machine. Among these are colored 

 sparks and vibrations determined in a platinum wire 

 traversed by a current of interrupted quantity, a pheno- 

 menon which can account for the effects produced in 

 telephones by a simple wire crossed by a current. 



Th. Du Marcel. 



To be continued. 



ON A PROCESS FOR UTILIZING WASTE PRO- 

 DUCTS AND ECONOMIZING FUEL IN THE 

 EXTRACTION OF COPPER* 

 Bv J. Dixon (Adelaide, South Australia.) 



This paper contains an account of a process for ex- 

 tracting copper from sulphurous ores, in which the heat 

 generated by the combination of the oxygen of the air 

 with the sulphur of the ore is utilized for the smelting of 

 the ore. This process is based upon experiments, which, 

 although the author regards as incomplete, show (1) 

 that the charge grows visibly hotter by simply blowing 

 air through it ; (2) that the melting of the raw ore or 



regulus and its reduction can be carried on in the same 

 furnace; (3) that if the ore is in lumps, and fed at the 

 top whilst the air is admitted by the side, a practically 

 clean slagg can be obtained ; but if added in a coarse 

 powder, as it is generally found in the market, it either 

 blows out again or chokes the furnace ; (4) that a rough 

 copper of about 96 per cent pure metal can be obtained 

 by the successful working of this process. 



ON THE CHEMICAL ACTION BETWEEN 

 SOLIDS* 



By Prof. Thorpe, Ph. D., F.R.S. 



The author drew attention to the extremely rare in- 

 stances of such action hitherto observed, showing how 

 many of these might be explained on the supposition 

 that combination actually occurred between the bodies 

 either in solution or in a state of gas. For example, the 

 formation of cement steel, by the combination of carbon 

 with iron, which had long been adduced as an example of 

 such combination between solids, was now explained by 

 the fact that iron at a high temperature was permeable 

 to gases, and that in the actual process of cementation 

 oxides of carbon were formed, which were in reality con- 

 veyors of carbon to the metal. He then illustrated by 

 experiments the formation of several compounds by 

 bringing together the components in solid form, 

 choosing as examples such as would manifest 

 their formation by characteristic coloring. Thus, 

 as instances, potassium iodide and mercuric chloride, 

 potassium iodide and lead nitrate, and silver nitrate and 

 potassium chromate, were powdered together in a mor- 

 tar, and in each case evidence of an action was exhibited 

 by the production of characteristic colors of the product 

 of the reaction of these compounds. The author re- 

 ferred to the memoir of the Belgian phycisist, Prof. Spring, 

 on the same subject, some of whose experiments he had 

 repeated and in the main confirmed. One of the most 

 remarkable results obtained by the Belgian professor was 

 the formation of coal from peat by subjecting the latter 

 material to a high pressure. Peat from Holland and 

 Belgium, when exposed to a pressure of about 6,000 at- 

 mospheres, was, according to Spring, changed into a 

 mass which in all physical characters resembled ordinary 

 coal. Experiments of the same nature made by Dr. 

 Thorpe with various samples of British peat yielded, 

 however, a very dissimilar result. These experiments 

 were made with pressures which were considerably less 

 and more than those employed by Spring. Although 

 solid, compact masses, hard and very much changed in 

 structure, were attained, in no case was any product ob- 

 tained which could be confounded with bituminous coal. 

 He said it was highly improbable, on purely chemical 

 grounds, that mere pressure had been little more than an 

 important factor in the transformation of woody matter 

 into coal. 



A NEW DEMONSTRATION OF THE CARBONIC 

 ACID OF THE BREATH. 



By C. F. Cross. 



Some time since I made the observation that the car- 

 bonic acid of the breath determines the liberation of iodine 

 from a mixture of potassium iodide and iodate, and that 

 the presence of starch renders the decomposition a very 

 effective lecture-experiment, in demonstration ot the 

 presence of an active acid body in respired air. A friend 

 to whom I lately communicated this result, threw doubt 

 upon my interpretation, and while admitting the 

 occurrence of the decomposition under the condition of 

 respiring vigoiously into the solution, preferred to at- 

 tribute it to the action of the air or of acid vapors acci- 

 dentally present. I therefore repeated the experiments 



♦British Association, 1S81. 



British Association, 1SS1. 



