ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 821 



mous extent ; it constituted an addition of energy wliieh was equivalent 

 to the creation of millions of workmen. The steam engines at work in 

 civilised countries represent the labour of ten or twelve times the total 

 number of adult males in the population of the world. This was an 

 acquisition of power, but not of intelligence. 



But after these two inventions, the one warlike, the other industrial, 

 there came one belonging to science, that of the Microscope and Tele- 

 scope, which has had no parallel in history for the extent and the effects 

 of its material results. Outside the world as perceptible by our senses, 

 there was, above and below, a sort of immense envelope, which had for 

 thousands of years escaped the eyes of man. Beyond the boundaries of 

 the visible, both in the large and the little, there was, as it were, a second 

 sphere, vaster than that in which so many generations had lived, which 

 had remained up to that time an impenetrable domain. One day, thanks 

 to what I shall call the new eyes with which man learnt to endow himself, 

 the previously unknown world was revealed to us ; and we know now 

 whether it contained sufficient subjects of interest and wonder. 



Viewed thus in its glory, the double invention of the Microscope 

 and the Telescope appears a sudden thing. Yet this great and extra- 

 ordinary extension of the sense of sight was not altogether new. 

 Primitive man could not remain a stranger to certain facts of magnifica- 

 tion which, so to speak, forced themselves upon his attention. 



When I was living in the Antilles, I once saw a black, who had been 

 brought from his native land of Africa before the suppression of slavery, 

 and who was consequently a savage, looking through a drop of dew at 

 a gnat upon a leaf. This was a temporary observation, unintentional 

 and the effect of chance ; still it was none the less an observation, and 

 the chance would naturally recur in certain circumstances. Primitive 

 man could not then be entirely ignorant of the magnifying power of 

 drops of water. . . . 



The two instruments, the Microscope and Telescope, thus appear to 

 us as proceeding from the same germ. We see that they were produced 

 at the same time, the beginning of that 17th century to which they were 

 destined to reveal so many marvels, and in the same form, namely a 

 convex lens associated with a concave lens. The first improvement was 

 made contemporaneously in both, by the substitution in. both cases of a 

 convex for a concave eye-piece ; for the Telescope in 1613 by Scheiner at 

 the suggestion of Kepler, for the Microscope in 1618 by Francesco 

 Fontana. Both profited, so to speak, by Huyghens' idea of using three 

 lenses, and both were at the same time invested with a new power by the 

 application of achromatism. There is a further resemblance ; the names 

 of the two instruments remained vague and to some extent confused ; the 

 Academy dei Lincei, at Rome, judged it necessary to have distinct names, 

 and a Greek, named Eemiscianus, settled in Italy, supplied the two 

 words Microscope and Telescope ; so that the two instruments born 

 together received baptism at the same time, after having shared every- 

 thing at their entrance into the world. 



If they have subsequently separated, and if they tend to separate 

 more widely in their construction, it is only in consequence of the 

 different purposes to which they are applied. Practical convenience has 

 led by degrees to distinct arrangements adapted on both sides to the 

 conditions which they have to satisfy. But this diverging course should 

 not make us forgtt the original similarity of the types. . . . 



1888. 3 K 



