548 THE POPULAR SCIENCE MONTHLY. 



of the Association to collect around him a choice circle of specialists, 

 and in particular to show much attention to Berzelius, who was at that 

 time on a visit to Berlin. Yon Humholdt gave a breakfast in honor 

 of Berzelius, which was remarkable for the number of celebrated men 

 who were present at it. After the breakfast a drive was arranged 

 to Humboldt's country-seat at Tegel. Here the host exhibited the 

 art-treasures of his brother William, and afterward the whole party- 

 drove to the quarry of Riidersdorf, where geology was discussed by 

 the learned company. On this occasion, Wohler has reported that it 

 was very interesting to watch the contrast between Humboldt's well- 

 known inexhaustible powers of conversation and Berzelius's quiet de- 

 meanor. Wohler, being the youngest and slightest in stature, had a 

 seat in a dog-cart between Humboldt and Berzelius. While on the 

 way to the quarry, in the midst of one of Humboldt's harangues, Ber- 

 zelius turned to Wohler and said in Swedish : " O Lord, how this man 

 does talk ! I can't stand it much longer ! " Wuhler was greatly em- 

 barrassed for fear that Humboldt would overhear the remark, but, as 

 he kept on talking, this anxiety vanished. 



This was, perhaps, the most prolific period of Wohler's life, for at 

 this time he published his famous researches on aluminum, glucinum, 

 yttrium, and, in association with Liebig, on cyanogen, cyanic and uric 

 acids. Gay-Lussac had proposed the question in the early part of the 

 century whether, when cyanogen was treated with alkalies, a cyanic 

 acid might not be produced, and it was in answer to this question that 

 Wohler published his first paper in Gilbert's " Annalen " in the year 

 1822. It was at the same time that Liebig, then a boy in years, had 

 gone to Paris to show Gay-Lussac what he had done in the same direc- 

 tion ; and it was Humboldt who aided the boy chemist in Paris, just 

 as he did Wuhler in Berlin in later years. Subsequently, as we have 

 seen, Wohler and Liebig made common cause of this investigation, and 

 published their researches together. But the most important research 

 of Wohler falls in the year 1828. 



This was the artificial production of urea. This investigation 

 forms an epoch in the history of chemistry. Previous to this time 

 the so-called organic world and the functions of vital force were be- 

 lieved to constitute a realm by themselves. Berzelius had said dis- 

 tinctly in his great text-book that we should never be able to imitate 

 the products of vital force in our laboratories. We could destroy and 

 could build up material things, but to imitate the vital forces would 

 always be impossible. Wohler, at the age of twenty-eight, overthrew 

 this theory and created a revolution in the domain of chemistry. He 

 made a breach through what appeared to be an impenetrable wall, and 

 this opening has gone on increasing ever since, until it would appear 

 as if, in a few years, no wall would be left standing. Berzelius's esti- 

 mate of the value of the research on artificial urea is given in a most 

 genial letter which he wrote to Wuhler in January, 1831, and which 



