Samuel Lewis Penfield. 355 



to the highest degree, while giving them a training of the 

 greatest value. Penfield, who took to analytical chemistry 

 with the keenest eagerness, no doubt in great part had his 

 future career determined by his work during these two years 

 and the one following, when he was transferred from the chem- 

 ical to the mineralogical laboratory as assistant. 



During this period he analyzed the new minerals eosphorite, 

 triploidite, dickinsonite, fairfieldite and fillowite, and made 

 analyses also of triphylite, childrenite, amblygonite, cymato- 

 lite, spodumene, etc. Up to this time his work, though deal- 

 ing largely with minerals, had been entirely of a chemical 

 nature and it is certain that he expected to make chemistry the 

 subject of his life work, for in the years 1880-1881 he went 

 to Germany to obtain advanced instruction in the organic side 

 of this science. He spent two semesters in the laboratory of 

 Prof. Rudolph Fittig at Strassburg and a part of the work 

 resulted in the publication with him of a joint paper on organic 

 compounds prepared and studied. He heard some lectures 

 under Prof. P. Groth, at that time located at Strassburg, but 

 there can be no doubt that, had he known the work he was to 

 do in the future, his studies would have been almost wholly 

 under the direction of this eminent teacher and crystallog- 

 rapher. He never regretted, however, the time he had thus 

 spent, for it added greatly to his general knowledge of chem- 

 istry and to his training in the solution of chemical problems. 



It was at the close of this stay in Germany that the oppor- 

 tunity opened which finally determined Penfield's career in 

 science. The constant growth of the Sheffield Scientific 

 School had laid such an increasing burden of executive duties 

 upon its director, Professor Brush, that he was no longer able 

 to give more instruction in mineralogy in the institution than 

 was involved in the course of lectures on the descriptive side of 

 the subject and suggestions and advice in advanced work. 

 The practical work in the subject in the laboratory, the deter- 

 minative mineralogy, was given by his assistant, who, at that 

 time, was the late Dr. G. W. Hawes. The authorities of the 

 National Museum offered the latter an opportunity to develop 

 a department of Geology, which he accepted, and Penfield 

 was called to fill his place. He entered on his duties with 



