PROCEEDINGS. 277 



the waut of sympathizing friends following the same line of studies, with 

 whom he could have exchanged opinions on questions too complicated to be 

 settled without the experience aud co-operation of other observers, he never 

 lost courage, and his botinical writings, extending over the period from 1833 

 to 1886, were published in various papers and journals of this coast, but 

 principally in the proceedings of this Society. The plants described by him 

 number over two hundred, and a complete list, carefully sought from all 

 sources, was published, in 1885, in the thii-d of our Bulletins. 



He was one of the founders of our Society, and the last one living; no 

 other face was so familiar to our members as his, and his cheerful and ami- 

 able character endeared him to all. Of late years be very rarely attended 

 the meetings of the Adademy, feeling the weight of advancing years and 

 preferring to study and work at home. He usually spent, however, some 

 portion of nearly every day in the Academy building, devoting his time for 

 several years past to making drawings of trees and shrubs of California— 

 "pretty pictures," as Le used to call them in his quaint way. 



His guileless simplicity and honesty, as well as his enthusiasm for science, 

 made him beloved by all; in all the relations of life his conduct was beyond 

 praise. Those who knew him in early days remember well his filial devotion 

 to his aged mother, and all who had the pleasure to be in daily intercourse 

 with him, praise, with me, his kindness, his patience, aud his forbearance. 

 Peace be to his ashes ! 



The President announced the death of Frederick H. 

 Jenssen, resident member. 



Dr. Behr read the following memorial. 



Dr. Frederic Jenssen, was born in the year 1847, on the island of Eugen, 

 and studied natural sciences at the universities of Greifswald and Berlin. 

 His studies were directed chiefly to chemistry and especially to explosive 

 compounds, in which department he became a recognized authority and was 

 for some years so employed in the great tunnel of St. Gothard. 



In the year 1880, he emigrated to Peru, hoping to find in the warm and 

 dry climate of its coasts, relief from the laryngeal affection from which 

 he suffered, and to which he finally succumbed. While there he received an 

 invitation to come to California and occupy an honorable aud hacrative place 

 in the service of the Giant Powder Company, which position he retained till 

 near the time of his death. 



During the whole time of his residence he continued experiments and 

 studies in his specialty, and has at various times contributed to scientific 

 societies valuable observations on the causes of so-called "spontaneous ex- 

 plosions" and similar subjects, till lingering disease put a stop to investiga- 

 tions of the highest practical merit. 



Dr. Jenssen was only forty years of age when death interrupted the 



