53 
opinion, and yet he must be prepared at any moment to relin- 
quish it when a single clearly contradictory fact is encoun- 
tered.” “ The philosopher,” says Faraday, “ should be a man 
willing to listen to every suggestion, but determined to judge 
tor himself. He should not be biassed by appearances; have 
no favourite hypothesis ; be of no school ; and in doctrine have 
no master. He should not be a respecter of persons, but of 
things. Truth should be his primary object. If to these 
qualities be added industry, he may indeed hope to walk within 
the veil of the temple of nature.” He may indeed, and when 
there we should have from him fewer crude speculations when 
facts are absent ; fewer fallacious reasonings when logic can 
nowhere be found ; less talk about that which is inherently 
impossible, contradictions between the science of God's creation 
and that of creation’s God. We may hope, however, that the 
establishment of schools for original investigation and mental 
discipline will eventually produce students competent to see 
facts truly, describe them accurately, and infer from them 
reasonably ; qualities very much needed in the present 
day. 
I shall select my first illustrations from the beautiful dis- 
coveries by spectrum analysis. The stars, we know, resemble 
the sun in being sources of light and heat, not mere reflectors, 
as. are the planets. It was therefore inferred that whatever 
might be discovered regarding the physical constitution of the 
sun, would be in great degree true of them also. The telescope 
however could not afford us much information here, because to 
it they are but points of light. However, the spectroscope 
decided the question, and confirmed the supposition by showing 
that their spectra were similar in kind to that of the sun. But 
a still more striking confirmation of a cautious deduction, one 
regarding the motions of the stars, has been yielded by it. 
Giordano Bruno was, I think, the first to suggest that as the 
planets moved round the sun, the stars also had planets revolving 
round them ; and not only so, but they also themselves moved 
in space. This guess, since proved by direct astronomical 
observation, has received additional confirmation by the fact 
that the spectroscope can distinctly detect such motion in the 
change of the hydrogen line, caused by the different effect pro- 
duced on the retina by light when the luminous body is 
stationary, from that produced when it is in motion. There is, 
however, a difference in the rate of motion as yielded by spectro- 
scopic and by telescopic observation; that given by the 
spectroscope being about 29 miles per second for the star 
Sirius ; while that given by the parallax of M. Abbe is 43 ; 
