LETTER 18. RAIN-WATER 125 
on examining it, I descried no animalcules. (Note. My 
closet standeth towards the north-east,’ and is parti- 
tioned off from my antechamber with pine-wood, very 
close joined, having no other opening than a slit an inch 
and a half high and 8 inches long, through which the 
wooden spring of my lathe passeth. ‘Tis furnished 
towards the street with four windows, whereof the two 
lowermost can be opened from within, and which by 
night are closed outside with two wooden shutters; so 
that little or no air comes in from without, unless it 
chance that in making my observations I use a candle, 
when I draw up one casement a little, lest the candle 
inconvenience me; and I also then pull a curtain almost: 
right across the panes.) 
The 10th of June, observing this foresaid rain-water, 
which had now stood about 24 hours in my closet, I 
perceived some few very little living creatures,’ to which, 
because of their littleness, no figure can be ascribed; and 
among others, I discovered a little animal that was a bit 
bigger, and that I could perceive to be oval.* (Note. 
When I say that I have observed the water, I mean I 
have examined no more than 3, 4, or 5 drops thereof, 
which I also then throw away; and in narrowly 
scrutinizing 3 or 4 drops I may do such a deal of work, 
that I put myself into a sweat.) 
' From the situation of the house, this indicates that the “ closet”? was 
at the front, looking on to the canal in the Hippolytusbuurt.—Plate XX is 
inserted here to show the sort of house which L. probably lived in, and to 
illustrate what he means by fowr windows with two wooden shutters over 
the lowermost. (This picture may conceivably have been painted from L.’s 
own house—or Vermeer’s!) Although the original painting (formerly in 
the Six Collection, now in the Rijksmuseum) is now known as Het Straatje 
(= The Little Street), it appears to have been more correctly described as 
“A View of a House in Delft” in the catalogue of the sale of Vermeer’s 
pictures at Amsterdam in 1696. 
* Probably Monas (or Cercomonas): see below. 
* From the observations recorded later, it appears probable that the 
organism was a ciliate; but its very small size is against this interpretation. 
It may have been a Cyclidiwm. 
