80 The Ohio Journal of Science [Vol. XVIII, No. 3, 



This necessitated small sized apparatus, and meant in the case 

 of stoneware a manufacturing time of about two months for 

 the clay working, drying and cooling after firing. Attempts 

 have been made for many years to replace this material by metal. 

 Platinum, silver and gold are used in special cases, but while 

 these metals can be made into any size apparatus, cost is 

 prohibitive for most uses. Two classes of alloys have now been 

 developed: rare metal alloys, such as tungsten, chromium, 

 or nickel irons, and more recently the cheaper and more resistant 

 silicon-iron alloys. Extensive trials in the last two years have 

 shown the usefulness of these alloys though they do not possess 

 quite the resistance of stoneware to corrosion. They are known 

 under varying trade names, such as durion, made here in Ohio, 

 tantiron, and ironac. They are very resistant to all strengths 

 of sulfuric and nitric acids and are used with great satisfaction 

 in their manufacture and permit plants to run for months 

 without shut down. The success of the modern tower system 

 displacing platinum for concentrating sulfuric acid has been 

 largely due to the use of pipes and fittings of this alloy. 



Early in 1915 the demand for nitric acid for war purposes 

 increased to enormous proportions resulting in extensions to 

 old nitric acid plants and the erection of new ones larger than 

 the world had ever seen. Deliveries on stoneware jumped 

 to six months and even longer and had the production of 

 nitric acid been dependent upon stoneware alone, as a few years 

 ago, it would have been greatly curtailed and the story of the 

 great war would have been different. As these alloys can be 

 secured on short notice, the same as cast iron, chemical manu- 

 facturers do not hesitate if a still should run wild and froth 

 sodium sulfate into the condenser to direct workmen to break 

 the connections at once with a hammer and allow the expelled 

 material to flow on the floor, thus preventing the wrecking of 

 the condensing apparatus. New castings can replace the broken 

 one at once. Such extravagant handling of the material 

 would not be possible under the usual slow deliveries with 

 stoneware. This freedom from risk of damage to condensers 

 and the making of condensers themselves of this material, 

 enables stills to carry a heavier charge and be operated at 

 greater speed. Where the old equipment charged 2000 lbs. 

 once or twice in twenty-four hours, these war-time stills operate 

 on 0000 lbs. of nitre, plus 4000 lbs. of sulphuric acid, charging 



