Volume 11

Alle de brieven van Antoni van Leeuwenhoek / uitgegeven, geïllustreerd en van aanteekeningen voorzien door een Commissie van Nederlandsche geleerden.

  • Antonie van Leeuwenhoek
Date:
1939-
Catalogue details

Licence: Public Domain Mark

Credit: Alle de brieven van Antoni van Leeuwenhoek / uitgegeven, geïllustreerd en van aanteekeningen voorzien door een Commissie van Nederlandsche geleerden. Source: Wellcome Collection.

    37/406 (page 21)
    Letter No. 149 [91] 20 July 1695 at C, and many others stuck to the glass and to the substance from which they had been formed. This again was a sight that was not unpleasant, because many particles of the said substance were forced up, one even with greater speed than the other, accord¬ ing to the size of the air bubbles and the size of the particle of the substance to which they adhered. After I had left the said glass device standing for about ten hours and thus could be certain that the air formed in the glass bulb CDE could not escape there¬ from and enter our common air, I observed the glass device and saw that the air bubbles were diminished by more than one half; and after a further six hours I saw only few air bubbles and after a further six hours I saw only very few air bubbles; after the glass device had been left for nearly twenty-four hours, I saw only one air bubble, which was no larger than a grain of common sand, and these air bubbles were among the largest I have seen emerging from the substance; and the said last remaining air bubble I could see no longer after a further nine hours. I was amazed at this sight, viz. the formation and disappearance of the air bub¬ bles, because I could not understand for one thing how this formation of air took place, and for another how the air changed into another substance again, and fur¬ ther that when many air bubbles lay close together they did not combine16). But I here stop thinking about it and leave it to the philosophers. Thus far I had got with my notes, which I had made last winter, since when I Salt crystals frequently, when cleaning my Ears, put the substance from the Ears also in a small from ear-wax. glass device as illustrated above in Fig. 3 by ABCDE. And having also poured fig. III. rain-water on it, I resumed my previous observations in the Month of July and saw repeatedly as large a number of air bubbles emerging from the said substance and disappearing again as I have said above about the substance off my Feet. I also placed several glass [tubes] with the said watery substance in the air after previously the substance from the Ears, which was also admixed with many little scales forming our epidermis, had sunk to the bottom and all the upper portion of the water had become reasonably clear. .6) brane. The fact that the air bubbles do not unite is probably due to the enveloping oily mem- [Han.]