5C)2 PHILOSOPHICAL TRANSACTIONS. [aNNOISqS. 



the same since in the optic nerves of 4 horses' eyes; and if it be not allowed 

 that the sight is thus performed, yet it must be granted, that great plenty of 

 new matter continually thus flows from the brain for the nourishment and gene- 

 ration of the eyes. 



I examined the gall of a trout, and found a great quantity of small globules, 

 smaller than blood-globules, and a still greater number of much smaller ones, 

 scarcely to be discovered by my best microscopes; so that I think, it impossible 

 the liquor should be so very fluid, unless these globules sometimes changed 

 figure, and that easily as they pass by each other. But what method soever I 

 made use of, yet I could not discover any salt particles therein, which was my 

 aim. — I observed the skin of a very large eel, and found the scales on the back, 

 and belly in straight rows one upon another, but those on the sides were some 

 sloping towards the belly, others towards the back, but all downwards. Exa- 

 mining the matter or slime covering these scales, which is generally thought 

 to come from without to the scales, whereas it is a real part of the body itself, 

 furnished with capillary vessels, and veins admirably interwoven ; some of which 

 are so very slender, that if a common blood-globule was divided into lOOO 

 parts, one of these could yet scarcely pass them. That slime also which covers 

 the bream is nothing but a kind of cuticle, though its vessels are so very 

 small as to require a very excellent microscope ; and this substance is likewise 

 covered with extreme minute globules. This commonly called slime, does not 

 only proceed from the innermost skin of the fish, but partly out of the scales. 

 I viewed the scales of perch, and found them likewise furnished with a similar 

 kind of slime or skin ; the difference being only in that the vessels forming it 

 are much stronger, so that it is not so easily rubbed off, and is defended by little 

 pricks sticking out at the ends of the scales. 



I set some beer- vinegar in my closet ; and after 8 or 10 days, I found a great 

 number of salt particles in it, sharper than those I had formerly seen in wine- 

 vinegar. In some I saw a little cavity in the middle : others seemed not per- 

 fectly formed, wanting one point ; others were a great many joined together. 

 I put some crabs'-eyes into the vinegar ; and then the salt figures were so small, 

 and all encompassed with little particles, that I could not discover any perfect 

 salt particles. — ^Juice of lemons and citrons aflForded no salt particles ; but after 

 freezing, and a little settling at the bottom of the phial, the clear juice yielded 

 plenty of them, much like those of wine and beer- vinegar. — Spirit of sal am- 

 moniac, after a while exposing in my closet began to shoot, and examining 

 the figures, I found a great many small particles coagulated into one little mass, 

 each of which was a little longer than broad, with a little cavity, so that it seemed 

 as if they had been plain at first, and that the sides turned up. I viewed a 



