Colloids and the ultramicroscope : a manual of colloid chemistry and ultramicroscopy / by Richard Zsigmondy ; authorized translationby Jerome Alexander.

  • Zsigmondy, Richard (Richard Adolf), 1865-1929.
Date:
1909
Catalogue details

Licence: In copyright

Credit: Colloids and the ultramicroscope : a manual of colloid chemistry and ultramicroscopy / by Richard Zsigmondy ; authorized translationby Jerome Alexander. Source: Wellcome Collection.

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    gold mutually precipitate cach other. I therefore mixed solution B with AuPx. Before mixing, individual parti- cles were not to be seen in either, but a short time after mixing there could be seen a large number of bluish- green individual particles, having a brilliancy equal to that of gold particles about 15 [x in diameter, but a much less active motion. Hydrosol of Silver Iodid. A solution of silver nitrate (0.2 mg. AgNOß in 100 cc.) was mixed with a very dilute solution of KI. The immediate result was a perfectly clear fluid in which could be seen a blue polar- ized light-cone. At first no individual particles were visible, but after a long time extremely small particles having active motion could be seen, appearing as blue cliffraction-disks. April 7, 1902. After ten clays the particles became clistinctly visible by sunlight, their active motion persisting. Calculated from the measurement of the clistance between them, the approximate mass of these individual particles was 1014 mg. Lottermoser1 has also succeeded in producing con- centrated and quite stable Solutions of silver iodid. Dr. Lottermoser was kincl cnough to send me some of his preparation for examination; in this yellowish-white, milky hydrosol, the particles have already grown to considerable size. They are so closely crowcled in the concentrated fluid that it is a wonder that so many particles can continue to exist alongside of each other. The concentrated fluid, Lottermoser States, contained 0.98 grms. silver iodid in 100 cc. In it were seen num- berless white particles, rushing past each other as in a surging throng. One extremely important observation shoulcl be noted: isolatcd dust particles and threads, 1 Lottermoser, Jour. f. pr. Chem , 1903, Vol. LXVIII, p. 341.