VOL. XIX.] PHILOSOPHICAL TRANSACTIONS. ^J 



mentioned kind of animals. I found that tlie point of a pin dipped in spittle 

 would presently kill them all. 



In the surface of some mineral chalybeate water, which had stood in a phial 

 unstopped for about 3 weeks, I saw two kinds of animals, one exceedingly 

 small, and the other very large ; which latter sort had on the tail something 

 like fins ; there were but very few of either sort. The compounded salt or 

 vitriol of the water was shot into pretty figures, but all irregular. They looked 

 like a small heap of little sticks, laid across each other at all angles and posi- 

 tions, only they were transparent, and a little greenish, as crystals of a chaly- 

 beate nature use to be. 



I have infused whole pepper-corns, bay-berries, oats, barley, and wheat, in 

 water, whose scum, after 2 or 3 days, has afi-'orded animals, as has been often 

 already found by others, at least as to some of them ; but I found the greatest 

 numbers and variety in wheal and barley-water, and the fewest in that wherein 

 bay-berries had been steeped. 



How such vast numbers of animals can be thus, as it were at pleasure, pro- 

 duced, without having recourse to equivocal generation, seems a very great 

 difficulty to account for. But though the solving of it that way makes short 

 work of the matter, for it is easy enough to to say they are bred there by putre- 

 faction, yet the asserting equivocal generation seems to me to imply more 

 absurdities and difficulties than perhaps may appear at first sight ; I wisti there- 

 fore, that this matter would awhile employ the thought of some ingenious and 

 inquisitive man. In the mean time I have conjectured, that these animalcula 

 may be produced by one or both of the following ways. 



1. I have thought that the eggs of some exceedingly small insects, which are 

 very numerous, may have been laid or lodged in the plicae or rugae of the coats 

 of the grain, by some kinds that inhabit those seeds, as their proper places. 

 For that insects of the larger kinds do frequently thus deposit their eggs on the 

 flowers and leaves of plants, is often experienced, and it is very probable, that 

 the smaller or microscopical insects do the same. Now these being washed out 

 of the seeds, by their immersion in water, may rise to the surface, and there 

 be hatched into those animals which we see so plentifully to abound there. 



2. Or the surface of the water may arrest the straggling eggs of some micro- 

 scopical insects, that perhaps were floating in the air : and being fitted and pre- 

 pared for this purpose by the infusion of proper grain, or a proportionable degree 

 of heat, may compose so proper a nidus for them, that they may, by the 

 warmth of thf sun, be easily hatched into living creatures, which it is probable 

 may afterwards turn into flies, or winged insects of the same species with the 



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