TEE CHEMIST IN CONSERVATION 297 



and fuel, a real conservation of resources. More recently as nigh grade 

 ores suitable for the Bessemer process are becoming scarcer the metal- 

 lurgist has added to his equipment the open-hearth furnace in which 

 ores of a much inferior quality can be smelted. 



The history of aluminum offers an even more striking illustration. 

 For many years after it was isolated by Wohler from its fused halogen 

 compounds through the addition of metallic potassium it was some- 

 what of a chemical curiosity. Owing to the high cost of potassium the 

 lowest price at which it could be sold was several dollars an ounce. It 

 could not be bought in any large quantity. I distinctly remember the 

 pride with which one of my earliest teachers of chemistry was wont to 

 exhibit .to his classes a piece of aluminum about as large as his finger, 

 and with what delight he would tell of Wohler's custom, in saying 

 good-bye to his newly made doctors of philosophy, of bestowing upon 

 those with whom he was particularly pleased a piece of the precious 

 metal, this being such a fragment. That was not many years ago ; yet 

 in 1907 there were produced in this country 17,000,000 pounds which 

 sold for about five million dollars — less than 30 cents a pound. And 

 this was the answer of chemists and metallurgists to the demand for a 

 light, permanent metal at moderate cost. What the future of aluminum 

 may be we do not know. But being in abundance, the second of the 

 solid elements and twice as large in amount as iron, its compounds can 

 not possibly be exhausted. 



Alizarin, which is one of the important vegetable dyes, was formerly 

 obtained from madder, the root of a plant growing abundantly in the 

 south of France and some other Mediterranean countries. The demand 

 for it increased until thousands of acres were given over to the cultiva- 

 tion of the Rubia tinctorum. But in 1868 two chemists, Graebe and 

 Liebermann, after long study, succeeded in preparing alizarin synthet- 

 ically from anthraquinon, a coal-tar derivative. It drove from the 

 market the natural alizarin. There was an outcry from those who had 

 cultivated the crude material that their means of livelihood had been 

 destroyed. But thenceforward the fertile fields which had been de- 

 voted to its growth were used to furnish foodstuffs to the country. A 

 waste substance had been used and the old energy turned into better 

 channels. 



A similar history is that of indigo, one of the standard dyestuffs of 

 our grandmothers — a product of the indigo plant. Adolf von Baeyer, 

 chemist, of Munich, in 1870 overcame the difficulties of its synthetic 

 formation and, from coal-tar again, by complicated methods prepared 

 this substance, one of the most stable of our dyes. Other chemists have 

 simplified the process until now it is formed in the factory, a rival of 

 that from the field, and thus large tracts of land are released for other 

 forms of agriculture. 



