174 LEEUWENHOEK AND HIS ‘“‘ LITTLE ANIMALS ” 
they have seen 10,000 living creatures in a parcel of 
water the bigness of a millet-seed, while others say 
80,000 and also 45,000. I have generally counselled 
these Gentlemen, when giving their testimony, to put 
down but half the number that they judged they had 
seen; for the reason that the number of animalcules in 
so small a quantity of water would else be so big, that 
’twould not be credited: and when I stated in my letter 
of 9 October, 1676, that there were upwards of 1,000,000 
living creatures in one drop of pepper-water, I might with 
truth have put the number at eight times as many. For 
if there be, as the testimonial saith, 45,000 animalcules in 
a quantity of water as big as a millet-seed, then 
3? there would be 4,140,000 living creatures in a 
50000 Crop of water: and over and above this vast 
4050000 number, I cau say that I am able to discern at 
4140000 times even as many other living creatures, which 
are so little that they were hid from the sight 
of the Gentlemen who gave their testimony. ‘The first 
number, when doubled, amounts therefore to 8,280,000 
living creatures in one drop of water. This is incon- 
ceivable: but let us put it thus, that supposing a coarse 
grain of sand be divided into 8,000,000 parts, then I do 
indeed see little living creatures in water which are no 
bigger than these particles of sand would be. And this 
being conceived, ’twill not appear so marvellous. 
The attestations' of the eight eye-witnesses have for- 
tunately been preserved with the foregoing letter. There are 
actually five of them, but one bears three signatures and 
another two—making eight testimonies in all. One® is in 
1 Presented at a meeting of the Society on 15 October 1677, and read on 
November 1 [0.8.]. Cf. Birch, Vol. III, pp. 346, 347. 
? By Alexander Petrie, son of a more famous father of the same name 
(ca.1594-1662) who was a Scottish divine and minister of the Scottish 
church at Rotterdam. The father’s life will be found in Dict. Nat. Biogr., 
but I have been unable to discover anything further about the son—the 
present writer. 
