586 SUMMARY OF CURRENT RESEARCHES RELATING TO 



througli a lens explains the expressions already quoted, from Roger 

 Bacon, Fracastoro, del Porta, Lodovico delle Colombe, and Alimberto 

 Mauri, who repeatedly mention images brought near and enlarged by 

 the use of converging lenses, and they show their belief that with 

 appropriate lenses one can bring nearer and then enlarge the images of 

 most distant objects, and especially of the stars. These expressions 

 only really reveal the lack of knowledge in those times of the manner 

 in which vision is effected, and of the function of lenses in the forma- 

 tion of images. 



From all that we have now set forth it appears suflBciently demon- 

 strated that at the beginning of the seventeenth century they had already 

 possessed for more than 300 years lenses capable of enlarging the 

 images of objects, that this enlarging power of the lenses was known, 

 but that no one until then had made any use of it as a simple Microscope 

 to study things more minutely and to progress in the knowledge of 

 nature. (38) 



It was the discovery of the Dutch telescope, and still more the 

 celestial discoveries made by Galileo, which drew the attention of the 

 learned towards lenses and their properties, and the passage of Wodder- 

 born, mentioned at the beginning of this paper, permits us to affirm that 

 if the Florentine philosopher was not the inventor of the telescope (as 

 he has himself candidly declared in many places), he was without doubt 

 the inventor of the compound Microscope, having used from 1610 a 

 Dutch telescope to look at near and minute objects, and having discovered 

 with it various details unknown by him till then in some common 

 animalcules, on which the learned men of those days did not deign to 

 fix their eyes, intent as they were in seeking the origin, reason, and 

 properties of things in Aristotle's Category and in the artifices of 

 laboriously barren dialectics. 



Contrary, therefore, to the conclusions of the Abbe Rezzi, we must 

 affirm that Galileo did not invent the simple Microscope, because it had 

 already been invented for centuries, but invented instead the compound 

 Microscope with a convex and a concave lens, and was the first to make 

 use of it to increase our knowledge of natural things. 



To better secure for Galileo the invention of the compound Micro- 

 scope one might have quoted also the words of Viviani in the life of his 

 master published by Salvini in the 'Fasti Consolari,' (89) and those 

 placed by the same Viviani on the front of his house in Florence in Via 

 Sant' Antonino (formerly Via dell' Amore), No. 13. (40) But the 

 enthusiastic admiration of Viviani for Galileo has made him many times 

 fall into such exaggeration with regard to Galileo's discoveries, that it 

 lessens the authority of his words, especially in the matter of optics, of 

 which it does not appear from his writings that Viviani ever understood 

 very much. 



Neither, for the same reason, will we quote the ' Oratio de Mathe- 

 maticse laudibus habita in florentissima Pisarum Academia cum ibidem 

 publicam illius scientise explicationem aggressus foret' (Romae, Typo. 

 Jacobi Mascardi, 1627, dto) of Niccolo Aggiunti, disciple of Galileo, 

 although it may be useful to recall the passage where Aggiunti, speaking 

 of Galileo's Microscope, says, " dudum vero telescopioli usu ita sensum 

 visus exercuimus, etc. etc.," for also from these words, pronounced in 

 1626, one fiuds that the occhialino of Galileo was a small telescope 

 (telescopiolum, a word which for Aggiunti, as for others, then meant only 



