BENJAMIN SILLIMAN. coe 
examining and reporting on mines, His mining explorations 
at this time were extended into Arizona; and one of the vol- 
umes of this Journal for 1866, contains an account by. him of 
his trip to the Mojave desert, Fort Mojave and the San Fran- 
cisco Mining district. This visit covered the period of his 
father’s death at New Haven which occurred in November of 
that year. A second visit to the Pacific States, for a similar 
purpose, was made by him in the year 1867, and still another 
in 1872; and after 1872, his journeyings as a mining expert 
carried him over nearly all the rest of the Rocky Mountain 
region within the limits of the United States. 
Mr, Silliman’s scientific publications are numerous and cover 
a wide field. In 1846, his father’s work on chemistry having 
been long out of print, he published his “ First Principles of 
Chemistry,” The work had many excellent features, was 
highly valued in the country and met with great success, more 
than fifty thousand copies of the three editions (1846-1853) 
having been sold. In the part of the work on Organic Chem- 
istry he had the assistance of Dr. T. Sterry Hunt. About ten 
years later, in 1858, appeared another work, of somewhat sim- 
ilar nature, entitled the “ First Principles of Physics or Natural 
Philosophy ;” a second edition of it was published in 1860. 
For the work the author modestly claimed, in his Preface, only 
the credit that « belongs to a faithful digest and compilation 
- from the best authorities in modern science.” The volume con- 
tained a vast amount of matter, well arranged for instruction, 
ad. for many years it was the best known of Physical text- 
ks in the country. 
Mr. Silliman’s papers in this Journal are more than fifty in 
number, and embrace a wide range of subjects. The larger 
Part are descriptions of minerals, more especially from the 
chemical side, and among the papers are many of prominent 
terest: on the composition of Calcareous Corals (1846) ; on 
the new species, Emerald Nickel, from Texas, Pa. (1847); the 
