588 SUMMARY OF CURRENT RESEARCHES RELATING TO 



the too great proximity of the object to the lens or by the too great 

 distance of the image from the eye. Briicke's idea therefore was 

 excellent, and anatomists, physiologists, botanists, and naturalists, who 

 continually use that small Microscope (microseopietto) of his, have 

 justly, out of gratitude, called it " BrucJce's lens." 



But properly speaking, however, this lens is only a telescope of 

 Lippersheim or of Janssen, and therefore a Microscope of Galileo. 

 " It is clear (says Briicke himself) that it depends on the same principle 

 as the Galilean telescope. The compound Microscope is an astrono- 

 mical telescope whose objective has a very short focus ; if instead one 

 gives a very short focus to the objective of a Galilean telescope, we 

 obtain the lens just described." 



This frank confession of the celebrated physiologist proves with 

 what candour he admitted having first used as a Microscope the Dutch 

 telescope, and does not even allow the suspicion that he had had the 

 least idea that Galileo had been before him even since 1610, that is, in 

 the year of his wonderful discoveries in the heavens. We must not, 

 however, deprive Briicke of the merit of having invented for the second 

 time the Microscope, composed of a convex and a concave lens, all the 

 more so, as his " working lens " is not intended to examine small objects 

 or to see invisible things, but has been made and is used for anatomizing 

 at some distance on those organs or those tissues which only demand a 

 small enlargement to be sufficiently recognized. 



APPENDIX. 



Whilst this paper was being printed. Prof. Antonio Favaro with 

 great kindness communicated to me an important passage, the better to 

 confirm Galileo as the inventor of the compound Microscope. This 

 passage is taken from certain ' Eelazioni dei Viaggi ' of Giovanni du 

 Pont, Seigneur de Tarde, Canon of the Cathedral of Sarlat (Dordogne), 

 ' Eelazioni ' which are in MS. in the National Library of Paris (Fonds 

 Perigord, t. vi. cart. 20 and following). From these ' Eelazioni ' it 

 appears that on Tuesday, November 11th, 1614, Tarde arrived at 

 Florence, and on Wednesday the 12th went at once to visit Galileo, 

 who was ill in bed. After having spoken with him about the Celesti 

 discoveries, Tarde relates that Galileo told him : — 



" Que le canon du telescope pour voir les estoiles n'est pas long plus 

 de deux pieds, mais pour voir les objects qui nous sont fort proches et 

 que nous ne pouvons voir a cause de leur petitesse, il faut que le canon 

 aye deux ou trois brasses de longueur.- Avee ce long canon il me diet 

 avoir vu des mouches qui paraissent grandes comme un agneau et avoit 

 appris qu'elles sont toutes couvertes de poils et ont des ongles fort 

 pointues, par le moyen desquelles elles se soutiennent et cheminent sur 

 le verre, quoique pendues a plomb, mettant la pointe de leur ongle dans 

 les pores du verre." (" That the tube of a telescope for looking at the 

 stars is no more than two feet in length, but to see objects which are very 

 near, but which we cannot see on account of their small size, the tube 

 must have two or three lengths. He tells me that with this long tube 

 he has seen flies which look as big as a lamb, and had learned that they 

 are all covered over with hair, and have very pointed nails, by means 



