Feb, 24, 1876] 



NATURE 



337 



than nitrogen from the air. They have found that 1,000 litres 

 of charcoal absorb 925 lit. of oxygen and only 750 lit. of nitrogen. 

 When moistened with water, 350 lit. of oxygen and 650 lit. of 

 nitrogen are given off; so that 575 lit. of oxygen and 55 lit. of 

 nitiogen remain, which may be extracted by means of the air 

 pump. By repea'ing the same process with this gaseous nuxture, 

 they succetded in obtaining oxygen in almost a pure state. 

 WTiether this method was ever employed on an extensive scale 

 is unknown. But this has been the case with Mallet's ^ method, 

 founded on the higher coefficients of absorption of water for oxy- 

 gen, as compared with nitrogen. The coefficients of absorption of 

 these gases m water areoo25 for nitrogen, and 0046 for oxygen. 

 Multiplied by their volumetric proportion in the atmosphere 

 079 and o'2i, these figures yield the proportion in which 

 these gases occur in water = 00197 N and 00097 O 5 or» the air 

 absorbed in the water contains in one volume o 67 S', and 033 

 O. If the non-absorbed nitrogen is cow allowed to escape, and 

 the absorbed mixture of the two gases is extracted from the water 

 and submitted a second time to absorption, we shall find by 

 muliiplying their coefi&cients with the numbers just obtained, 

 0*67 (N) and 0*33 (O^, that the mixture now absorbed will con- 

 tain o'525 X and 0475 ^- -^ third absorption will raise this 

 proportion too-375 N : 0-625 O ; a foiuth to 025 N :075 O; a 

 fifth to 015 N : 0"85 O ; that is the same relation in which the 

 gases occur in the mixture ordinarily produced by Tessie du 

 Motay's process. After the eighth absorption, the gas evolved 

 is almost piue oxygen (0973 O and 0*027 X). 



Mallet's apparatus consists of a greater or smaller number of 

 strong iron water- reservoirs, ccrmected by forcing and sucking 

 pumps. Into the first air is pumped through fine openings, at 

 a pressure of about five atmospheres. After this the non-ab- 

 sorbed nitrogen is removed by opening a valve, and then by means 

 of the second forcing and suckirig pimip the absorbed gas is drawn 

 out of the first vessel and forced into the second. With four 

 vessels a complete operation is performed in five minutes. If 

 the vessels vary in size, decreasing from the first of 10 cb.m. to 

 the fourth of 5 cb.m. in capacity, uninterrupted working will 

 produce a result of 7,760 litres of a mixture containing 75 per 

 ctnt. of oxygen per hour ; or, 168 cb.m. in twenty -four hoars. 

 The cost of working and keeping this system in order is said to 

 be trifling, and a small amount of superintendence will suflBce if 

 the machine is made automatic. Where working power is 

 cheap, such as water power, or the lost heat of metaUurgical 

 processes, these methods might possibly be of use, especially 

 for metallurgical processes themselves, which could be effectually 

 assisted by mixtures containing a smaller proportion of oxygen. 



Summing up the practical results of this long list of inven- 

 tions, we find in the foremost rank the well-established rrelhod 

 of Tessie du Motay. The next place is taken by the mechanical 

 method of Mailet, just described ; which, however, has not yet 

 met with a practical verification. 



We arrive at last at the question. What oses has pure oxygen 

 hitherto served ? As the supporter of combustion, we arc 

 indebted to it for warmth and light ; as a means of respiration, 

 it is the foundation of our lives. 



Let us look at it then, from these three points of view. Its 

 metallurgical uses claim our first attention. The important part 

 it has performed in the history of platinum has been already 

 desaibed. We have learned to do without it in lead soldering ; 

 hydrogen or coal gas, burnt in air, supplying a sufficient quantity 

 of heat. The example of this industry encourages us to cherish 

 the greatest hopes for its further and wider employment. "Just 

 as gold," sajs an esteemed metallurgical chemist,* " while it was 

 still used in soldering platinum, destroyed its appearance by yellow 

 marks, in the same way white soft solder offends the eye when 

 applied to coloured metals. This unsightliness induced the 

 Society for the Promotion of Industry in Prussia to offer a prize 

 for the discovery of a yellow solder. It would be difficult to 

 solve this question, unless a new easily fusible metal of a red ur 

 yellow 3 colour could be discovered. A better chance of success 

 offers in the self-soldering of metals by means of the oxyhydrogen 

 blow-pipe, which has already gained triumphs in the manipula- 

 tion of two metals of different natures. Is it not possible with 

 this powerful agent, which has succeeded in soldering lead 

 with lead, and platinum with platinum, to soldtr every other 

 metal and every alloy, just in the same maimer ; as tin with tin, 



» Mallet, Dingl. poL J. da, 112, and Philipps on Oxygen, Berlin, 1874, 

 24 ff. 



* Clemens Winkler, Deutsche Industrieblatter, 1871, S. 182, andZeitschr. 

 d. Vereins deutsch. Ingen. x>t. 714. 



3 For which reason the offer of reward has since that time been with- 

 drawn. 



copper with copper, brass with brass, silver with silver, gold 

 with gold, and even iron with iron ? 



'* The probability of such an innovation exists, and there is no 

 question of the tangible benefits to be derived from it. 



"We need only picture to ourselves the neatness of a work- 

 shop in which soldering is effected by means of a light, elegant 

 gas burner, instead of the soldering iron or forge ; the workman 

 remaining uninjured by the glowing heat, smoke, and vapours, 

 able at any moment, by the turning of a cock, to regulate the 

 supply of heat with the greatest nicety. We need but look at 

 the solidity of a soldering which no longer depends on a foreign 

 substance, but is the actual blending together of the two parts, 

 thus saving material and work, as no filing of the soldered part 

 would be required. Such palpable advantages must silence 

 every prejudice, and give a strong impulse to the setting on foot 

 of thorough and persevering researches on this subject." 



Since oxygen has become cheap, however, its use has likewise 

 been recommended in that lai^est branch of metallurgy, the pro- 

 duction of iron and steel. 



Cameron^ advises the use of oxygen or ecriched air, as 

 produced by Mallet's absorption cylinders, instead of common 

 air from the bellows for high furnaces ; and here it will be well 

 to remember that the absorption of oxygen in water has already 

 accidentally contributed to this result, in a manner which leaves 

 room for improvement Br. Kerl ' calls attention to the fact 

 that air from water blowing machines is richer in oxygen than 

 common air. Besides, it has already been observed that char- 

 coal, when stored up, bmns with increased vigour, because it has 

 absorbed oxygen from the air, and that this forms a valuable 

 assistance in refining iron.^ 



Knppelwieser •• recommends oxygenised air for the Besse- 

 mer process, and he is of opinion that the price of Tessie du 

 Motay's method need not be greatly reduced to allow the use of 

 oxygen for this purpose. A great fiiture seems here to dawn on 

 the application of oxygen ! Nevertheless, we must not omit Le 

 Blanc's ' objection, that the necessity of using fire-proof mate- 

 rials woold render the economical advantages very question- 

 able. 



But turn from the metallurgical application of oxygen to its 

 use for illuminating purposes. The discovery of the oxyhydro- 

 gen light by Drummond^ in 1826, and its employment in 

 smveying and for lighthouses, has destroyed every doubt as to 

 the value of oxygen for these purposes- The reduction of the 

 price of oxygen brought it into wider use. This time America 

 led the way. 



H. Vogel ' found oxygen successfully employed in New York 

 in 1870, not only for lighthouses, signals, and ordinary buildings, 

 but also to illuminate the beds of rivers, for the building of 

 bridges, and for various appliances of the magic lantern. The 

 building of the great Brooklyn Bridge over the East River, then 

 in an early stage of construction, was facilitated by twelve 

 oxyhydr(^en lamps, which consumed about 2,000 cubic feet® of 

 oxj^en daily. Instead of chalk cylinders, the more durable 

 zirconiom-cones were employed with great advantage, and in 

 the same way the Theatre de la Gaite and the Alcazar, in Paris, 

 were lit up with fairy-hke brilliancy. In the opera house in 

 New York, a diagram of about ten square metres was thrown 

 on a screen of damp muslin, the lamp placed behind the stage, 

 prcducing wonderful effects. The magic lantern has with Sie 

 help of this light become very popular in lecture rooms, for the 

 projection of apparatus, glass-photographs, and drawings, 

 especially since Outeibridge ^ taught us to draw pictures with 

 pen and ink on thin gelatine plates. The effects are easily ex- 

 plained when we remember that the oxyhydrogen gas yields a 

 light sixteen-and-a-half times stronger than the same quantity of 

 ordinary gas would yield. 



The daily amount produced in 1870 by the New York Oxygen 

 Company was 30,000 cubic feet {850cb.m.) The oxygen is sold 

 in iron cylinders (patent of Robert Grant, New York), nine 

 inches in diameter and thirty inches in length, which are filled 

 with oxygen tmder a pressure of twenty to thirty atmospheres, 



I Cameron, Bcrg-n. Hutten Zeitnng, 1S71, 132. 



' Br. Kerl, Gnindriss der Huttenkunde, L, 217. { 



3 J. pr. Chem. ci. 397 ; Bergwerks Fieund, iiL 513. 



4 Kuppelwieser, Biorg-u. Hutteu Zeitung 1873, 354. 

 3 Le Blanc, Jcumal f. Gasbeleucthuog, 1872, 641. 



6 Drummond, On the means of facilitating the cbssvadon of di^^ant 

 stations in geodetical opeialions. PhiL Trans. 1836. 



7 H. Vogel, Ber. Chem. Society, iii. 901. 



s In V<^cl's Report, cubic metres is printed by mistake. 

 9 Mmton, Journal of the Franklin Ipstitute, Lii. liv. It. See also Vogel in 

 the passage quoted before 



