Heinrich Rose. 327 
by which their presence may be ascertained. This part of my 
work has been enlarged, in each new edition, by numerous ex- 
periments. The rarer substances have al ways more particularly 
attracted my attention; and I have given to them the more con- 
sideration, in proportion to the difficulties of their detection and 
recognition. 
enriched science in the last eight years; I submitted them to 
examination in the laboratory, and I added to them the results 
or the many researches which I have myself undertaken for the 
sake of this work. Lastly, every portion of the book has been 
carefully revised, and I do not hesitate to say that, after so much 
pains, it is become an entirely new work, rather than a'new edi- 
n of my former Manual. 
Ss, 
as offering in a practical form a compendium of the 
_ Whole Science, Rose can claim a three-fold merit for his book. 
0 his last year he was engaged in preparing an abridgment of 
his great work, for which a number of new experiments were 
Making. About thirty sheets of it were printed at the time 
of his death. The modesty which led him to avoid mention of 
* While we full i 
gars y appreciate, from our o 
Beneral scheme of qualitative analysis devised by Rose, and feel how ; 
is indebted to him for its introduction, we venture to suggest that the value of 
consists, in the first place, in its teaching the beginner not to rely 
of individual tests, but methodically to separate each constituent 
their application; and secondly, as furnishing a general idea of the m 
all analysis ought to be performed. We would 
wn experience, the great utility of the 
much the sci 
- 
arni e that 
uantitative analysis, which requires the student often to depart fro: 
s laid down for aoa tative paso, wot al and to recognize and think about 
h m ercise upon each other, is the only 
surely to detect them; and that qualitative 
© performed with certainty, so long asthe promis consents to follow gen- 
8, or, still worse, systematically arranged tables. 
; y 
