VOL. XV.] PHILOSOPHICAL TRANSACTIONS. J 47 



I thought I saw many that had a hollowness within thentij like that of a boat; 

 sometimes one of the figures appeared, the one half brown, and the other part 

 clear ; sometimes one of the figures lay across another, as at E. Sometimes 

 there were figures which seemed to have been cut in two, each of them repre- 

 senting but one half of A, B, or C, as F. Many of these figures were so small, 

 as scarcely to be seen, but so numerous that I judged them to be many thou- 

 sands in one small drop of vinegar. These particles I take to be the sharp 

 pungent matter, which causes the sense in the tongue, which we term sour. 



Having put into a glass about 2 inches wide, a little vinegar, which was 

 sufTered to stand on my table for 8 weeks. In this time I found swimming on 

 the surface of the vinegar many particles, within which I perfectly discerned a 

 hollowness like to that of the inside of a boat ; for the figures were now in- 

 creased in thickness. Those that had the cavity turned to the eye, were as 

 fig. G ; those whose sides were turned to the eye, which had only part of the 

 cavity to be seen, were as fig. H. I have also described a full grown live eel, 

 as fig. LM, of which there were many more in the vinegar. As also a full 

 grown eel which I killed, that the designer might see it more distinctly, as fig. 

 NO. This also may serve to show the size of the salt particles, compared 

 with that of the eels. 



I took several new glasses with vinegar, and put in them some crabs' eyes, 

 split into small pieces, lest the grit that comes from them, when pounded, 

 should hinder my sight : I found that the long sharp figures which might be 

 likened to a weaver's shuttle, were now changed into figures, whose basis was 

 oblong, rising up pyramidally, like a pointed diamond, as N° 2, fig. P. Others 

 had their basis square as fig. Q. Others an irregular quadrilateral, as fig. R. 

 But these last two figures, I supposed were accidental, for want of sufficient 

 matter to complete, and perfect them on all sides. The number of particles 

 was so great, that in a gross computation I judged them to be 6000 in a drop 

 about the size of two barley-corns. But that which I most wondered at, was, 

 that these salt particles here, were almost all of the same size : a thing I never 

 observed in any other salt before. 



I took some vinegar out of a glass, that had crabs' eyes in it, at a time be- 

 fore all the air-bubbles were ascended : but even then the basis of the salt par- 

 ticles was four-square, and not as in common vinegar. The liquor had quite 

 lost its acidity. I took also white chalk, beaten to pieces, and put it in vinegar, 

 where it caused as a great commotion and rising of air-bubbles, as the crabs' eyes 

 had done : it produced also the same figures of the salt, and the same in- 

 sipidness. 



When blood has been sometime out of the veins, small salts then begin to 



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