While the evils to which science is exposed by the necessarily unfashionable character of experimental manipulation are neither few nor trivial, there are still evils which arise from the directly opposite cause--from excess of intellectual cultivation; as is shown in the exclusive love of mathematics by a great number of philosophers. Minds which, left to themselves, might have eliminated the most valuable results, have, dazzled by the lustre cast by fashion upon abstract mathematical speculations, lost themselves in a mazy labyrinth of transcendentals. The fashion of mathematics has ruined many who might be most useful experimentalists; but who, wishing to take a higher flight, seek to attain distinction in mathematical analysis, and having acquired a certain celebrity for experimental research, dissipate, in simple equations, the fame they had acquired in a field equally productive, but not so select. Like Claude, who in his later years said, "Buy my figures, and I will give you my landscapes for nothing;" they fall in love with their own weakness, and estimate their merit by the labour they have undergone, not by the results they have deduced. M. Comte expresses himself well on this subject. "Mathematicians, too frequently taking the means for the end, have embarrassed Natural Philosophy with a crowd of analytical labours, founded upon hypotheses extremely hazardous, or even upon conceptions purely visionary; and consequently sober-minded people can see in them really nothing more than simple mathematical exercises, of which the abstract value is sometimes very striking, without their influence, in the slightest degree, accelerating the natural progress of Physics."[21] [21] Cours de Philosophie Positive, vol. ii. p. 409.