386 



SCIENCE 



[N. S. Vol. XXX. No. 769 



and on this farm Professor Johnson spent 

 his boyhood. He thus early became famil- 

 iar with practical agriculture. 



His father's training and experience in 

 business led him to take a keen interest in 

 the problems presented to the farmer and 

 his discussion of such questions awakened 

 an interest in his son to know more of the 

 principles upon which the processes de- 

 pended which he daily saw in progress 

 about him. 



At the age of ten he entered the Low- 

 ville Academy where he remained seven 

 years and there came under the influence 

 and instruction of David Porter Mayhew, 

 who was an enthusiastic student of the 

 natural sciences. Mayhew had then re- 

 cently secured the means of establishing a 

 chemical laboratory and in this laboratory 

 Professor Johnson obtained his first 

 knowledge of chemistry and, as he once 

 wrote, "there became fascinated with 

 chemistry through the brilliantly illus- 

 trated lectures of the principal." May- 

 hew made him his assistant, and, in 1846, 

 presented him with a then recently pub- 

 lished translation of Fresenius's Chemical 

 Analysis. The possession of this book led 

 him to equip a laboratory at his own home 

 in which he prepared most of the reagents 

 described, and worked through the quali- 

 tative course. 



In his first note-book, dated June, 1848, 

 he described his laboratory as nearly com- 

 pleted and begins with an account of his 

 first attempt to prepare distilled water. 

 This book contains many interesting ac- 

 counts of the difficulties he encountered in 

 preparing his reagents, and gives an in- 

 sight into the training he thus got at the 

 beginning of his chemical career which 

 left its marked impress on his habits of 

 work and thought throughout the re- 

 mainder of his life. 



The ability to rely on his own resources 



and to overcome difficulties by persistent 

 effort soon developed a degree of self-con- 

 fidence which enabled him to continue his 

 studies in the face of difficulties which to 

 most boys of his age would have seemed in- 

 surmountable. Although his father was 

 interested in his chemical work he consid- 

 ered it an uncertain means for gaining a 

 livelihood and opposed his son's determi- 

 nation to adopt it as his life work. He 

 therefore undertook to show that he could 

 support himself and so engaged in teach- 

 ing in various schools at intervals for three 

 years. 



Having saved some money he entered the 

 laboratory at Yale in 1850 and continued 

 his studies with Benjamin Silliman and 

 John P. Norton. His funds giving out, he 

 again took up teaching and was so success- 

 ful that his father became convinced that 

 he had the capacity to take care of himself 

 and decided to give him an opportunity to 

 gain the education he had determined to 

 secure. 



After returning to Yale for another year 

 he went abroad in 1853 and entered Erd- 

 mann's laboratory in June, where he 

 stayed until the next April, studying 

 various problems in organic and inorganic 

 chemistry as well as attending lectures in 

 other subjects. The next year he spent in 

 Munich in the laboratory of Liebig and 

 also studied with von Kobel and Petten- 

 kofer. As a student at Munich he won the 

 respect and friendship of Liebig, who fol- 

 lowed with interest his later career and 

 for several years after continued a corre- 

 spondence with him. In 1855 he went to 

 Paris, where he attended Chevereul's lec- 

 tures. He spent the summer in England 

 and worked for a short time with Frank- 

 land. 



In September he returned to New Haven 

 and took charge of the laboratory of the 

 Yale Scientific School as chief assistant in 



