104 M. RaspaiPs experiments on the granules of Pollen. 



But it is well known that the power of 1000 diameters can 

 never be compared in point of light and distinctness with infe- 

 rior magnifying powers ; and even if a microscope should mag- 

 nify 1500 times, the advantage derived from it would perhaps 

 be inferior to that gained by a single lens, for clearness is un- 

 doubtedly a great compensation for magnifying power. Of 

 what consequence is it to show us giants, if we can distinguish 

 them only in shadow. 



On the other hand, the diameter of organs which we re- 

 quire to study is far from being invariable ; and if a microscope 

 should not be able to magnify enough to show an organ in one 

 body, we may expect to meet with the same organ on a large 

 scale in another body, so that its examination will require only 

 a small magnifying power. If, for example, we had occasion 

 to study the fecula in the farina of the small millet, it would 

 be difficult to make the simplest experiment with a power of 

 1000, but the potatoe presents us with a fecula examinable by 

 very inferior magnifying powers. * 



The essential advantages consequently which can be derived 

 from high powers are only ephemeral in relation to natural 

 history ; and we ought therefore to be on our guard against 

 attaching to them too much importance. 



Supposing, however, that this importance is sufficiently 

 great to enable us to arrive exclusively at the knowledge of 

 truth, let us examine the question, whether this privilege 

 ought to be granted to the microscope of Amici in preference 

 to every other. 



The horizontal microscope of Amici does not absolutely dif- 

 fer from the vertical achromatic microscope invented by M. 

 Selligue but in having a triangular prism, the hypothenuse 

 of which reflects horizontally to the eye-glass the image trans- 

 mitted by the object-glass. The most superficial knowledge 

 of optics is sufficient to convince us that, cwteris paribus, i. e. 

 supposing the two microscopes to have the same system of 



• We cannot here agree with our author. The examination of the fe- 

 cula of the potatoe will never stand in natural history for the examination 

 of the fecula of the millet, unless the similarity of all fecula hatl been pre- 

 viously determined. But as this could only be done by the microscope, 

 the argument of our author has no force. We might as well infer the 

 structure of the sting of minute animals from that of the enlarged organ 

 in the wasp. — Ed. 



