ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 589 



of wliicli they keep themselves up and walk on glass, although hanging 

 feet upwards, by insarting the point of their nail into the pores of the 

 glass." 



Therefore in 1614 Galileo had not forgotten his Microscopo of 

 1610, and spoke of it pretty much in the same terms as he did after- 

 wards in 1624 to Aleandro, Faher, and Cesi. 



Another document, discovered by Prof. Favaro in the National 

 Library at Florence (Cod. viii. F. 2), and by him also kindly passed 

 on to me, speaks of three ' Occhiali detti di moltiplicatione ' sent to the 

 Grand Duke from countries beyond the mountains ; and Agnolo Marzi 

 Medici, author of the document, adds that he cannot say how these 

 occhiali are made, being forbidden to do so, " because they want to see if 

 Galileo will be able to discover it, as it is over a month since ho is 

 working at it, and so far nothing has been seen." 



Now, although the document has no date, I think wo may unhesitat- 

 ingly attribute it to 1624, in the interval between the 11th of June, 

 when Galileo left Eome to return to Florence, and the 5th of September, 

 the date of Bartoloraeo Imperiali's letter thanking Galileo for the gift 

 of an occhialino. Galileo himself, writing to Cesi, September 23rd, 

 excuses himself for the delay in sending the occhialino because he had 

 not sooner brought it to perfection. Now, starting from Kome on the 

 15th of June, and this may be seen from a letter of Mario Guiducci, 

 11th of June, Galileo would not have reached Florence before the 

 21st June, and of one by Ciampoli (' Carteggio Galileano,' of Campori, 

 p. 206), who thanks Galileo for having received news of his safe 

 journey. 



On the 9 th August Antonio Santini wrote from Genoa to Galileo to 

 thank him for having had the occhialino perfected for Imj)eriali 

 (ib., p. 211), and as Santini answered a letter of Galileo of the 24th 

 July, so we must suppose the occhialino to have been finished at least 

 on that day. But if Imperiali's occhialino was finished on the 24th of 

 July, we must admit that shortly after the middle of July Galileo had 

 already found a means of bringing it to perfection. One can therefore 

 conclude that Marzi- Medici's ' Scritto,' written a month after the time 

 Galileo had set to speculate on and work at the occhialino, must be 

 placed about the 15th July (a month, that is, after Galileo's arrival at 

 Florence), when he was intending to reduce his Microscope to per- 

 fection. 



On the other hand, the arrival in Florence of " occhiali di moltiplica- 

 tione " from regions beyond the mountains cannot be placed anterior to 

 the introduction in Italy of Drebbel's Microscope, that is before 1624 ; 

 and in 1624 Marzi-Medici, secretary to the Grand Duke Ferdinand II., 

 and author of the document, was still alive, as it appears from a certain 

 catalogue of Salvini that he died on the 31st October, 1628; we can 

 therefore assign with certainty a date very near the 15th July, 1624, 

 to the curious MS. discovered by Professor Favaro. 



[NOTES. 

 1889. 2 s 



