72 
POPULAR SCIENCE REVIEW. 
strong imagination, and to exceptional natural ability ; too little to the less 
brilliant qualifications of steady thought, self-development, industry, and 
perseverance.” 
The book is in five parts, the first containing a general view of the subject ; 
the second, general conditions of scientific research ; the third, personal pre- 
paration for research ; the fourth, actual working in the art ; and the fifth, 
various special methods of discovery, classified, and illustrated by numerous 
examples. 
It is impossible in a short notice to go through the mass of matter con- 
tained in over 600 pages ; but attention may be drawn to the remarks in 
Part II. on “ unexpected phenomena,” on “ unexpected or accidental disco- 
veries,” in which, quoting Whewell, the writer lays down the rule that “ no 
scientific discovery can with any justice be considered due to accident. In 
whatever manner facts may be presented to the notice of a discoverer, they 
can never become the materials of exact knowledge, unless they find his 
mind already provided with precise and suitable conceptions by which they 
may be analysed and connected.” Very much the same remark was quaintly 
made by Aristotle in the aphorism that “ All knowledge comes out of things 
known before.” 
The whole third part is deserving of study by those in charge of promising 
and intelligent pupils. It will tend to lighten the heavy responsibility 
resting on them. The following passage deserves quotation : “ To be born 
before the time is almost as unfortunate as to be behind it. All original 
scientific investigators must, however, be more or less in advance of their 
time, otherwise they cannot be original at all. A scientific investigator may 
be before his age in more ways than one. Thus he may imagine and publish 
advanced and true hypotheses, the complete proof of which cannot be dis- 
covered until a later period. This was the case with Avogadro, and his 
hypothesis that equal volumes of different gases contain equal numbers of 
molecules. It is probably the case with some existing eminent men and 
their hypotheses. Or he may, as Galileo did, and Bruno shortly before him, 
publish his views and the proofs of them at the same time. But in either of 
these cases, if the views he publishes or even appears to hold, conflict with, 
or only appear to conflict with, the current creeds and unproved dogmas of 
theological belief, his character is privately attacked, and the minds of female 
members of his family (who can rarely understand science, but are easily 
influenced by feeling and religious emotion) are perverted, and his home 
happiness injured. In other instances his means of living are diminished. It 
is worthy of notice that every great pioneer of science, including even 
Newton himself, has been and still is accused by the ignorant of holding 
false opinions and beliefs, even in cases where those beliefs have been proved 
to be true. Retreating dogmatism continually says to the scientific investi- 
gator, 1 Thus far shalt thou go, but no farther,’ but science keeps marching 
on.” 
Part IV. describes the selection of a subject of investigation, the mode of 
conducting it, the value of many and various experiments, and of close 
measurements, the classification and explanation of results. 
The fifth part is more miscellaneous. Empirical methods of discovery, the 
extension of neglected or undeveloped parts of science, the use of new instru- 
