194 Peach Trees. 
been demonstrated—we have observed intense beauty of 
prismatic colours thrown from the interior of the Connecticut 
topaz, constant in certain positions, but not observable im 
others. The leading colours, which are very pure and in- 
tense, are blue, green, and red, sometimes in spots, but often 
in parallel lines, remarkably distinct, and much less blended 
at their confines, than uw Tl . 
Additional researches are to be made in the vein and the 
result will be communicated to the public. 
3. Dana’s Epitome of Chemical Philosophy.—A work of 
220 pages Svo. cannot be. expected to present much that is 
new in a science so extensive as chemistry. 
The author’s object is ‘ to furnish a work which should 
be useful as a text-book of the science, as it is usually taught 
in our academies and colleges,’ and he has endeavoured 
** to comprise the principal facts and doctrines of chemistry, 
in a condensed form, adapted to the use of those who wish to 
acquire a knowledge of the PHtLosopHy oF THE SCIENCE, 
ithout ‘entering into the details of laboratory practice, or 
being encumbered with the minutize of processes, and descrip~ 
tions of substances, which are interesting only to the profess- 
ed practical and operative chemist.” ' 
_ Dr. Dana appears to have executed his design with good 
judgment, and we doubt not that his work will be useful to 
arners, especially to those who wish to treasure up princi- 
_ ples, with the omission of details. ~ aa 
e have so many elementary chemical works, and so many 
good ones, that it can scarcely be i 
compile any thing new, except for the precise purpose of illus- 
trating a course of lectures, and for this purpose every lectur- 
er has undoubtedly the right to publish his own views and 
arrangement, for the benefit of his pupils and of others who 
may choose to adopt i .* 
eh otc Dana’s arrangement is clear—his style neat and per- 
picuous—his selections judicious, and he has introduced the 
most Rmportant facts and observations that have been made in 
this country. . See = 
4. Peach Trees.—A practical nursery man, now in the 
“: . Fequests us to state for the benefit of ‘the public, that 
e has discovered the cause of the decay of our peach trees, 
and also how, effectually, to remedy he. The cause is 
