Letters 193 



LETTER V 



To the most excellent and learned John Nardi, 



of Florence 



DISTINGUISHED AND ACCOMPLISHED SIR,- -The arrival 

 of your letter lately gave me the liveliest pleasure, and 

 the receipt at the same time of your learned comments 

 upon Lucretius satisfied me that you are not only living 

 and well, but that you are at work among the sacred 

 things of Apollo. I do indeed rejoice to see truly 

 learned men everywhere illustrating the republic of 

 letters, even in the present age, in which the crowd 

 of foolish scribblers is scarcely less than the swarms of 

 flies in the height of summer, and threatens with their 

 crude and flimsy productions to stifle us as with smoke. 

 Among other things that delighted me greatly in your 

 book was that part where I see you ascribe plague 

 almost to the same efficient cause as I do animal 

 generation. Still it must be confessed that it is difficult 

 to explain how the idea, or form, or vital principle 

 should be transfused from the genitor to the genetrix, 

 and from her transmitted to the conception or ovum, 

 and thence to the foetus, and in this produce not only 

 an image of the genitor, or an external species, but also 

 various peculiarities or accidents, such as disposition, 

 vices, hereditary diseases, naevi or mother-marks, &c. 

 All of these accidents must inhere in the geniture and 

 semen, and accompany that specific thing, by whatever 

 name you call it, from which an animal is not only 

 produced, but by which it is afterwards governed, and 

 to the end of its life preserved. As all this, I say, is 

 not readily accounted for, so do I hold it scarcely less 

 difficult to conceive how pestilence or leprosy should be 

 communicated to a distance by contagion, by a zymotic 

 element contained in woollen or linen things, household 

 furniture, even the walls of a house, cement, rubbish, 



