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.

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    tom, was forced up; nay, I saw little hairs from the Ear on which there were eight to ten air bubbles, which were also forced up. When I observed the glass [tube] where the substance from the Ear had touched it as it were when it was put in the glass [tube], again many air bubbles emerged. This sight was not unpleasant to me, because each air bubble, when I observ¬ ed it in front of the candle, showed the flame of the candle upside down. After this I took some substance from the Ear, which 1 separated into very small bits, and then pushed practically all the bits under water, in order that they should sink to the bottom, as happened with some of them, while others seemed to place themselves midway in the water; but after about one minute the air bubbles from the said substance had increased so much that the air bubbles forced the sub¬ stance14) up towards the surface of the water, also that which had lain on the bot¬ tom. And when the said substance had been in the water for a considerable time, and had been freed of the air bubbles, and also no more air bubbles were formed, the said substance sank to the bottom again. In my aforesaid observation it seemed to me that the air bubbles did not remain air bubbles, but disappeared again. In order to satisfy myself about this, I bethought myself of blowing the glass device of Fig. 3: ABCDE. Since I then lacked the substance from the Ears, I took off my under-stockings (which again had not been off my Feet for eight to ten days) and I gathered all the substance that was present between the Toes of my Feet, which I judged to have weighed only about one aes4)or i o^40~ a P°und15)- Having placed this substance in the glass bulb of Fig. 3 at D, I placed the glass device with A at the top, upon which through a small glass funnel prepared by me for this purpose, viz. FG in Fig. 4, I poured clean rain-water not only into the bulb of the glass device EDC, but in such a way that the bulb EB and the further part of the glass device was Filled up to A. This being so, I continued to hold the glass device somewhat with A at the top, in order that the small amount of air that might be present in the substance I had introduced into the glass device should escape from the glass bulb EDC. Having done this, I placed the glass device somewhat aslant again, as shown in Fig. 3, so that no water might flow out of it and the air bubbles which should be formed and should escape from the said substance, settling at C, could be observed through the magnifying glass. And after some hours I saw not hundreds, but sever¬ al thousands of air bubbles adhering to the glass and still rising, all of which settled fig. III. Air bubbles from sweat and skin near toes. fg HI- fig. IV. fig HI- 14) By the substance L. here apparently refers only to the floating particles. 15) Onepou«4is475 g.