H2 LEADING AMERICAN MEN OF SCIENCE 



"Very early after entering upon his professorship he made 

 many experiments with the blowpipe which had been invented, 

 not long before, by his friend Professor Hare. This apparatus 

 he greatly improved by an arrangement for storing the two gases 

 in separate recipients, and leading them to the burner by separate 

 tubes, so that they were united only at the tip, thus securing for 

 the first time entire safety from explosions. To him is also due 

 the name compound blowpipe by which the instrument was gen- 

 erally known. He continued the work of Hare upon the fusibility 

 of various materials, and added to the list many substances which 

 had hitherto been considered infusible. 



"For the more adequate illustration of the principles of elec- 

 tricity he had caused to be constructed a powerful battery of many 

 cells, then often called a deflagrator, by means of which he was 

 enabled to exhibit the phenomena of the voltaic arc with unusual 

 splendor and completeness. It was in the course of experiments 

 with this apparatus that he observed the fusion and volatilization 

 of carbon in the arc, and the transference of the carbon by the 

 current,, from the positive pole, where it left a crater-like cavity, 

 to the negative pole, where it built up a kind of stalagmitic ac- 

 cretion, considerably increasing the length of the pole. This re- 

 sult aroused great interest, and, though questioned by some, was 

 fully confirmed by Despretz and others who had repeated his ex- 

 periments. When the work of Gay-Lussac in obtaining potas- 

 sium from its hydrate was made known he successfully repeated 

 the experiment, and was doubtless the first person in the United 

 States to obtain the element in the metallic form. 



''These researches had met wide recognition and were esteemed 

 as of great interest and permanent value. But though the most 

 important, they constituted but a small proportion of his contribu- 

 tions to science. Numerous articles upon scientific questions 

 were published by him in the American Journal of Science and 

 elsewhere. Of these the Catalogue of Scientific Memoirs, pub- 

 lished by the Royal Society of London, enumerates by title 

 more than sixty, and several more which were published by 

 him in collaboration with others. Many of these contributions 

 were republished abroad, some of them in several different jour- 

 nals. 



"Among other professional labors, less strictly in the way of 

 scientific research, but still of value as original investigations, may 

 be mentioned a laborious exploration of the gold mines of Vir- 

 ginia, a study of the coal formations of Pennsylvania, and a 

 scientific examination of the culture and manufacture of sugar. 



