170 PHILOSOPHICAL TRANSACTIONS. [aNNO 1704. 



manifold small shining particles appeared to be wholly metalline. The said 

 matter was very hard, insomuch that when I struck it against a steel, it yielded 

 sparks of fire; I broke off a piece of it, and placing the remainder before a 

 microscope, it appeared as in fig. '23; the break of which is represented by gh. 

 On which side, the more I viewed it, the more I was persuaded that the many 

 small shining particles were certainly metalline; but when I brought it to the 

 fire, and endeavoured as much as I could to keep the smoke together, it ap- 

 peared plainly to be nothing but sulphur; which was manifest, both by the 

 smell, and because what was drawn ofF was of a yellow colour, just as sulphur 

 appears to the naked eye. 



That fig. 22 is a part of a real snail is clear to me; but how, and after what 

 manner, the sulphur gets into the shell, we c^n only guess. My opinion of the 

 matter is this: the snails, and other things that are found upon the mountains 

 of Switzerland, and which are supposed to be changed into metals, have lain, 

 and do still lie, where a great quantity of sulphur is shut up in the bowels of 

 the earth; and that sulphur, by a subterraneous warmth being rendered vola- 

 tile, mounts upwards in exceedingly fine particles like fire, and so insinuates 

 itself not only into the inmost parts of the snail-shell, where, according to all 

 appearance, the snail itself is almost consumed, but also into the pores of the 

 shell, and is there fixed and coagulated, so that the whole snail is converted 

 into a sulphureous substance. 



- Now, in order to show the exceedingly small particles, into which sulphur is 

 divided by fire, I prepared a small glass globe, represented by fig. 24, and 

 placed in it at b, a small particle of sulphur, about the size of a single corn 

 of sand; and when the glass and the air within it was of the temperature of 

 the air we commonly breath in, I sealed hermetically that part of the glass 

 which was open at e ; and then blowing the flame of a candle upon the other 

 part of the glass where the sulphur lay, till it evaporated into smoke, which 

 for a short time was carried about the glass in a circular motion; and after the 

 sulphureous smoke subsided, and settled itself on the glass, I examined it with 

 ^ microscope, and observed so many exceedingly fine particles on the sides of 

 the glass, that no man could believe that such a small grain of sulphur could 

 possibly be divided into so many parts ; insomuch, that the smallest globules of 

 this divided sulphur could hardly be seen with one of my best glasses, and the 

 largest globules lay round about the sulphureous matter that was not quite dis- 

 solved. After letting the glass sphere rest about half an hour, I observed with 

 surprise that some of the small globules of sulphur, that lay a little remote 

 from the rest, had formed themselves into a right line, and that 4 or 5 were 

 placed lengthwise; and some globules were so extended in length, that they 



