March i6, 191 6] 



NATURE 



61 



can has not been the slowest to move. It may 

 be that our people are too busy makings the things 

 required for munitions to be able to give the 

 matter adequate attention, but we could wish to 

 see the same signs of intelligent and organised 

 effort on the part of the general body of chemical 

 manufacturers in this country as we are now 

 witnessing on the other side of the Atlantic. There 

 can be no doubt whatever that with the fierce 

 industrial struggle that will certainly follow the 

 cessation of hostilities, a very serious time, fraught 

 with the greatest jjeril, is in store for us, and in 

 particular for our chemical industries. With 

 powerful rivals on either side of us, nothing but 

 the application of the same means, the same en- 

 lightened skill and intelligence that in the past have 

 brought pre-eminence to Germany, and are now 

 rapidly bringing it to America, can possibly save 

 i these industries from ultimate extinction. 

 I It is not our purpose to follow Mr. Waggaman 

 ' in his account of the methods of manufacture of 

 I sulphuric acid except in so far as they throw light 

 Ion their comparative advantages in special 

 I circumstances, or deal with questions peculiar to 

 : America. As regards the contact process, his 

 remarks as to its excellences and its commercial 

 limitations are judicious and to the point. It is 

 admittedly a process which demands skilled 

 land intelligent supervision, and in which there 

 lis no room for the rule of thumb type of pro- 

 cedure which characterises much of the fore- 

 jman management in this country. Doubtless the 

 last word has not yet been said on "catalysers " 

 land "poisons," and there is still room for the 

 ingenuity of chemical engineers in the improve- 

 jment of plant. But, as matters stand at present, 

 jfor certain grades of oil of vitriol, and especially 

 for those used generally in the manufacture of 

 fertilisers — one of the most important of the out- 

 lets of production — chamber acid will probably 

 hold its own for many years to come, especially 

 in view of the important improvements and simpli- 

 fications in plant and procedure which have been 

 ^introduced within recent years. 



Of the various methods which have been pro- 

 posed from time to time for accelerating the 

 chamber reactions, those which seem to have found 

 imost favour in the States are Pratt's, Meyer's, 

 iand Falding's. 



I In Pratt's process (U.S. patents Nos. 546, 596, 

 i'^52, 687), which appears to be much used in the 

 southern States, the gases are drawn through the 

 first chamber by a fan, then through a tower 

 packed with quartz, down which flows dilute sul- 

 phuric acid, when they are again introduced, by 

 the same fan, into the first chamber. In a number 

 [of plants in which this circulatory system is em- 

 ployed less than nine cubic feet of chamber space 

 iare required per pound of sulphur burned in 

 jtwenty-four hours. 



I In Meyer's arrangement, of which three instal- 

 jlations are in use in the States, " tangential " 

 chambers, designed so as simultaneously to mix 

 ^and cool the reacting gases, are employed. These 

 jchambers are cylindrical in form ; round the first I 

 Fun lead pipes conveying cold water. The gases ' 

 I NO. 2420, VOL. 97"! 



are admitted at a tangent near the upper part of 

 the chamber walls, and are discharged from out- 

 lets in the centre of the base, thereby acquiring 

 a spiral motion which tends to mix them thor- 

 oughly. 



In the Falding system the chambers are ap- 

 proximately one and a half times higher than their 

 horizontal dimensions. The gases after passing 

 through the Glover tower are introduced into the 

 chamber near the top, where, being hot, partly 

 from the fact that they have only recently issued 

 from the burners, and partly because their tem- 

 perature has been raised by the reactions between 

 certain of their constituents, they collect in the 

 upper part of the chamber and form an active 

 layer, which gradually cools and settles down to 

 the bottom of the chamber, where the spent gases 

 are drawn off. It is claimed that this system 

 requires much less chamber space in which to 

 complete the reactions than the ordinar}- type. 

 Each Falding chamber is a unit in itself, and is 

 connected directly w-ith the Glover tower, instead 

 of in series as in ordinary chamber systems. 

 Whatever doubts may exist as to the proper ex- 

 planation of the mechanism of the process, it 

 seems to be commercially successful, to judge 

 from the number of plants in which it is in opera- 

 tion. 



The new modification of the chamber process 

 to which Mr. Waggaman refers consists of a 

 method of more quickly effecting an admixture of 

 the reacting gases by causing them to traverse a 

 spiral tube of lead, kept at a determinate 

 temperature. The arrangement has only 

 been tried on a laboratory scale, but from the 

 published results it promises well. Whether it 

 will diminish the chamber space to the extent of 

 o'i39 cubic foot for everj- pound of sulphur 

 burned in twenty-four hours, as is claimed, seems 

 too good to be true. Comparative experiments 

 using glass and lead spirals app>eared to indicate 

 that the metal exerted a specific (catalytic) action. 

 The construction of a sulphuric acid plant along 

 the lines indicated by the author, if successful in 

 working, would certainly greatly diminish the 

 amount of ground space needed, and would pre- 

 sumably decrease the Initial cost of construction. 

 The practical man is apt to deride laboratory ex- 

 periments, forgetting that all factory experience 

 has its beginning in small scale trials. Perhaps 

 he may think it significant that " if patent is 

 allowed, it will be donated to the people of the 

 United States." 



^OTES. 

 Early in 1914 a committee representative of British 

 geologists and friends of Sir .\rchibald Geikie was 

 formed with the object of presenting to the Museum 

 of Practical Geology a suitable memorial of his long 

 association with that institution as director-general of 

 the Geological Survey and Museum, and as a record 

 of their appreciation of his brilliant labours in the 

 cause of geology. It was decided that the memorial 

 should take the form of a marble bust. On Tuesday, 

 March 14, a number of Sir Archibald Geikie 's friends 



