Volume 1
Alle de brieven van Antoni van Leeuwenhoek / uitgegeven, geïllustreerd en van aanteekeningen voorzien door een Commissie van Nederlandsche geleerden.
- Antonie van Leeuwenhoek
- Date:
- 1939-
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.
101/508 page 95
![one another, they do unite themselves close together7 8), and by this close conjunction the Blood that is under the surface alters its colour, and becomes dark-red or blackishs), as I have observed several times: of which I take the reason9) to be, (with submission to better Judgments) that the Air cannot move every way round about the Globuls, and hits as twere against a close darkish body. Touching the Florid red colour of the surface of the Blood exposed to the Air, that comes, in my opinion, from hence, that the upper¬ most Globuls are not press’d, and therefore retain their na- 7) The erythrocytes of blood taken from the body are apt to stick together on the concave side, forming cylindrical columns, so-called rouleaux. The significance which L. attributes to this formation of rouleaux for an explanation of the venosity of the deeper layers of the blood, is not necessary. The words in the Dutch text (literally: “close to and into each other”) seem to point to L.’s believing in an actual confluence, which would be erroneous. [H.] 8) The blood which is more deeply situated and excluded from the air assumes the colour of venous blood (reduced haemoglobin). [H.] 9) There is a striking ambiguity in the following exposition, where L. tries to explain his correct observation that blood exposed to the air is a brighter red near the surface, than in a deeper layer. This phenomenon is due to the oxydation of haemoglobine by the oxygen of the air, whereas the lower layers retain the colour of the poorly oxygenated venous blood. This ambiguity is owing to the fact that L. on p. 96 has „licht ofte lucht”. „Lucht” usually means “air”, but here it has the dialectal sense of “light”. The translator of the Phil. Trans, misunderstood the word and rendered the Dutch „lucht” by “air” instead of translating it by “light” (“Air or Light”). The copy has only “light”. Attentive reading will show that L. does not ascribe the reddening of the superficial layer to the action of the air — which would be correct as shown above — but to the penetration of light, reverberated from the lower layers, which surrounds the blood-corpuscles with its rays. Evidently it did not strike L. as improbable that a close darkish body should reflect light. [H.; M.] ill. 11.](https://iiif.wellcomecollection.org/image/b31364962_0001_0101.jp2/full/800%2C/0/default.jpg)
