142 NATURAL HISTORY. 



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. 



We have laboured, as may appear, in this inqui 

 sition of sounds diligently ; both because sound is 

 one of the most hidden portions of nature, as we said 

 in the beginning, and because it is a virtue which 

 may be called incorporeal and immateriate, whereof 

 there be in nature but few. Besides, we were 

 willing, now in these our first centuries, to make a 

 pattern or precedent of an exact inquisition ; and 

 we shall do the like hereafter in some other subjects 

 which require it. For we desire that men should 

 learn and perceive, how severe a thing the true in 

 quisition of nature is ; and should accustom them 

 selves by the light of particulars to enlarge their 

 minds to the amplitude of the world, and not reduce 

 the world to the narrowness of their minds. 



Experiment solitary touching the orient colours in 



dissolution of metals. 



291. Metals give orient and fine colours in dis 

 solutions; as gold giveth an excellent yellow, quick 

 silver an excellent green, tin giveth an excellent 

 azure : likewise in their putrefactions or rusts ; as 

 vermilion, verdigrease, bise, cirrus, &c. and likewise 

 in their vitrifications. The cause is, for that by 

 their strength of body they are able to endure the 

 fire or strong waters, and to be put into an equal 



