208 HISTORIA SONI ET AUDITUS. 



etiam, quia in visu non semper desideratur medium : 

 quandoquidem in tollendis cataractis oculorum, stylus 

 ille parvus argenteus, quo summoventur cataract, 

 etiam super pupillam intra tuniculam oculi movens, 

 optime cernitur. 1 



In objectis visus, si collocetur oculus in tenebris, 

 objectum in luce, bene habet ; si objectum in tenebris, 

 oculus in luce, non fit visio. Ita si velum tenue po- 

 natur ob oculos, aut reticulum, objectum bene cernitur ; 

 si super objectum, confundit visum. Atque licet fortasse 

 neutrum horum competat sono et auditui, tamen mo- 

 nere possunt ut fiant experimenta, utrum auris collocata 

 juxta truncum cavum, si sonus fiat ad distans in aperto ; 

 aut, via versa, sonus excitatus ad cavum truncum, auris 

 autem ponatur ad distans in aperto, promoveat magis 

 perceptionem sensus. 2 



De corporum diversitate quce reddunt sonum, et instru- 

 mentis, et de speciebus soni quce occurrunt. 



GENERA sonorum talem videntur subire partitionem : 

 magnus, parvus ; acutus, gravis ; harmonicus, absonus ; 

 summissus sive susurrans, exterior sive sonans ; sim- 

 plex, compositus ; originalis, reflexus : ut sint partitio- 

 nes sex. 3 



Quo fortior fuerit prima pulsatio, et delatio liberior 

 et absque impedimento, eo major editur sonus : quo 



1 Compare 215., and S. S. 272. 



2 " And it is tried that in a long trunk of some eight or ten foot, the 

 sound is holpen. though both the mouth and the ear be a handful or more 

 from the ends of the trunk; and somewhat more holpen when the ear of 

 the hearer is near than when the mouth of the speaker." Id. 130. 



8 - " There be these differences in general by which sounds are divided: 

 1. Musical, immusical. 2. Treble, base. 3. Flat, sharp. 4. Soft, loud. 5. 

 Exterior, interior. 6. Clean, harsh or purling. 7. Articulate, inarticulate." 

 Id. 290. 



