Miscellaneous Papers. 305 



intervention of the trained synthesist — that altruistic concomitant 

 of every crying need. 



Nor were proofs in any sense lacking. During a field trip to 

 New York we saw hydrochloric acid passed over hot bricks that had 

 heen impregnated with copper chloride ; the acid came out as chlor- 

 ine and water, while the bricks, with the saturant, were undisturbed. 

 During the same week we were shown that hydrogen sulphide from 

 the soda-tank "waste" of a soda factory was made to give up its 

 valuable sulphur by simply passing the gas above named into the 

 presence of acid and iron oxide. In like manner, by the passing 

 of the hydrogen sulphide into an area of hot chlorides of sodium 

 and copper, there were derived two valuable products, sulphate of 

 sodium and chlorine gas. Shortly after, upon being introduced 

 into the mysteries of a sulphuric-acid plant, we saw how roasted 

 sulphur gas and air, passed over, and scrubbed upon, and dried 

 upon, so to say, a platinized washboard, had produced that year 

 800,000 tons of sulphuric acid. Across the street an indigo factory, 

 where naphthalene was generated from coal tar and afterwards oxi- 

 dized by sulphuric acid in the presence of mercury and copper, was 

 daily tolling off a poem more glorious than any sung by Keats or 

 Byron — namely, a triumph-song of the achievements of man; a 

 panegyric of his power to harness and master the forces of nature. 

 Note, now, that even in this field the results attained were wholly 

 due to this same subtle catalytic power of certain substances over 

 other elements. 



In our daily rounds of sight-seeing in the metropolis we found 

 the photo-maker using this same faculty of well-known salts to 

 cheat Old Sol out of his rights of performance. For within that 

 artistic laboratory the cato-photo was no longer a dream, but a real- 

 ity. Be well assured we jotted down, right then and there, memo- 

 randa of the germane formulae processes: A solution of peroxide 

 of hydrogen and ether on the negative photographic plate gave an 

 invisible positive, by reason of the catalysis of the peroxide on the 

 silver-sensitized surface. Thereafter, by the use of manganous 

 sulphate, there was developed a beautiful brown tint, an alkaline 

 solution giving a perfect "carbon print" on the sensitized paper 

 used. On the return journey from New York even more of these 

 catalytic marvels were seen. In a Chicago laboratory we observed 

 the passing of ammonia from illuminating gas over platinum, with 

 air; the ammonia presenting itself, at the end of this process, as 

 nitric acid. Next in order, lead and manganese were found in use 

 as driers of linseed oil. A zinc-tube series, through which vapors 

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