./nines Dwight Dana. — Beecher. •» 
the crystallo-ehemical system now in use. Ye1 it was dune. 
not gradually, but all at once, as is stated in the preface to the 
third edition, ••notwithstanding the former adoption of what 
has been called the natural history system, and the pledge 
to its support given by the author in supplyingit with a Latin 
nomenclature, the whole system, its classes, orders, genera, and 
Latin names have been rejected, and even the trace of it which 
the synonymy might perhaps rightly bear has been discarded." 
Thus it is that Dana's text hooks have shown such life. 
Their author was not satisfied with a mere reprint for ;i new- 
edition, but each underwent revision, and was an ad- 
vance over the preceding. His active mineralogical studies 
were practically suspended after the publication of the fifth 
edition of the System of Mineralogy in L868, in which hi- en- 
listed the aid of Professor George J. Brush. The subsequenl 
thorough editing and revision of this ureal work has been 
carried on by his son. Edward S. Dana. 
President Dwight, who is most familial- with and compe- 
tent to speak of his work as a teacher. say>. "In the later 
years he gave instruction only in geology. The students were, 
however, glad to meet him when the privilege was given them. 
and no man in the company of teachers stood higher in their 
esteem both for character and attainments. They felt, as they 
saw him. that they were in the presence of a master in science 
and of one who honored the institution and themselves as lie 
lived in the academic community. He had the ardorof youth 
in his studies and in his instructions, even to the latest period 
of his active service. Notwithstanding the long-continued 
interruptions which he experienced by reason id' ill-health, he 
always returned to his work, even on partial recovery, with 
full enthusiasm. His walks with selected students in the 
country region about New Haven, and the teaching which lie 
gave as he moved from point to point, will ever he remem- 
bered by those who shared in the pleasanl excursions. As a 
lecturer he was attractive. His style was clear and impres 
sive ; his language admirably chosen; his manner adapted to 
his subject and material; his whole presentation of his 
thoughts and views thoroughly characteristic of a truly sci- 
entific man. He had a mingling of t lie poetic element in his 
writing which gave an interest to whal he said, and al times 
