88 PHILOSOPHICAL TKANSACTIONS. [aNNO J "04. 



1 have been often told that the cattle which feed in Siltagtig grounds, are free 

 from this disease of worms; but being informed that this kind of ground is very 

 low, and lies under water the most part of the winter, I gave the butcher these 

 reasons: why kine and sheep that feed in high clay grounds are troubled with 

 worms in their livers, and those in low grounds are free, is, only because the 

 low grounds lie all the winter under water ; for though such like worms may be 

 found in some of the low lands, yet as soon as they are overflov\ed with 

 water, those worms, abhorring the water, die immediately. To confirm my 

 reasoning, I took a glass tube, which at the upper end was about an inch wide 

 and above a foot in length; I put into it a little piece of the above-mentioned 

 earth* near 5 inches long, but so narrow, and the grass about it dipt so close 

 that it would easily go into the tube without pressing, and then poured upon it 

 boiled water, which had stood till it was cold : presently after I perceived that 

 several very small and long white worms came out of the earth, which reaching 

 and incurvating their bodies, subsided leisurely to the bottom of the tube, none 

 of them being able to emerge to the superficies: whence I concluded that they 

 could not live in the water; and in effect, after they had lain 24 hours in the 

 bottom of the glass, I found they were all dead. It seemed to me also that 

 these white worms consisted of several sizes or magnitudes, and that they could 

 not be the offspring of our common worms, because they were much longer, 

 in proportion to their thickness. I saw likewise a common worm creeping out 

 of the abovesaid earth, which leisurely subsided and remained at the bottom of 

 the tube, with little or no motion, and the next day it was dead. 



As for those small animalcula that came out of the earth, and swam about 

 the water, they were of so many several sorts and sizes, and were so exceedingly 

 small, that I could not j)erceive wh^t figure they were of, though I viewed them 

 very carefully and frequently, and though I shifted the earth and water three 

 times. 



Now that these animalcula may be called water-worms, though they are 

 found in the driest parts of the earth, appears from their living so well in the 

 tube filled with water, in which, though I observed them day after day, I found 

 no difference in them, save that they were increased in number, and besides I 

 have met with several of them in common water. 



At another time I went into one of the meadows near this town, which con- 

 sisted of a good clay soil, and lay as high as any about town; I dug out a little 

 bit of the said earth, about the size of a crown piece, which was covered with 

 clover-grass, short and fine ; imagining I should fird in the top of it some ani- 

 malcula, because I had formerly found in the rotten wood of a willow tree, and 

 in another rotten plank that had lain in the open air, some of those animalcula 



