EDITORIAL. 203 



and a clear thinkor, and to these qualities was added the rare gift 

 of expressing himself in clear, concise, logical English and of dis- 

 cussing scientific facts and theories so simply and effectively as to 

 put them within the understanding of those who had no previous 

 acquaintance with such matters. 



His first paper, in IS-tT, Avas On Fixing Ammonia, and was fol- 

 lowed a little later by others on county agricultural institutes, agri- 

 cultural education, contributions of science to agriculture, Wliat 

 is Science? agricultural charlatanry, the food of plants, and simi- 

 lar topics. The above all appeared prior to 1854, showing how early 

 his thought was turned to matters of popular instruction as well 

 as expei'iment in agriculture. 



Throughout his student daj's he was a constant contributor to the 

 agricultural press, especially the Cultivator and the Country Gentle- 

 man, and during the time he was abroad a series of articles from his 

 pen appeared in the latter paper under the head of " foreign corre- 

 spondence." These described in popular language the new basis of 

 agriculture as it was being worked out b}' foreign investigators, 

 together with items of interest from his travels. Among the subjects 

 discussed were Saxon agriculture, the new experiment station at 

 ]\Ioeckern — the first to be organized with j^ublic funds in any country, 

 the agriculture of Wiirttemberg and the agricultural academy at 

 Hohenheim, and the practical value of analj^ses of soils and of plants. 

 In 1855 he translated and abridged two of Liebig''s works on the rela- 

 tion of chemistry to agriculture, and wrote popularly upon theory 

 and practice in agriculture and the applications of science to the art. 



After Doctor Johnson returned to Yale he began the publication 

 of a series of articles on agricultural education, discussing in separate 

 parts the subject of agricultural science, the teaching of science, the 

 means of practical instruction, and the farm school. He likewise con- 

 tinued his popular writings on fertilizers and their use, the theory 

 of plant nutrition, and the physical properties of the soil as affecting 

 fertility. 



I*rior to 1853 Doctor Johnson took up the examination of com- 

 mercial fertilizers sold in Connecticut, and in 1858, upon his aj^point- 

 ment as chemist to the State Agricultural Society, he began publish- 

 ing a series of reports upon that subject, Avhich were probably the 

 first to be issued in this country. The early reports of the society 

 and of the board which followed it were enriched by his reports, 

 lectures, and essays, and became classic as an encyclopedia of agri- 

 cultural science. He delivered a course of lectures on agricultural 

 chemistr}' at the Smithsonian Institution in 1859, which were sub- 

 sequently published by the regents of that institution. 



In 1868 Doctor Johnson issued his classic treatise on How Crops 

 Grow, a book which has l^een more widely read and studied than any 

 other work on agi-icultural chemistry. This book was " a treatise on 



