Immunochemistry

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1907 edition. Excerpt: ...at lower concentrations both are supposed to be absorbed. This explication seems to me to have no advantage, to mean no more than the relation of the simple fact itself, besides being much more difficult to remember. Furthermore, it seems more simple to suppose that the reacting substance exerts two different actions on the cells, of which the one, appearing at higher concentrations, hinders the other, prevailing at lower concentrations. Such a behaviour is not rare in common chemistry. Thus, for instance, the addition of alkali to a solution of aluminium chloride gives a precipitate of aluminium hydrate, which is dissolved on further addition of alkali. In a brochure dealing with the properties of colloids Biltz1 1Biltz: Gottinger Nachricbten, math.-phys. Klasse 1904, I, Zeitschr. f. ph. Ch. 48. 615 (1904). recalls attention to the oft-observed fact that in general positive colloids (which wander in the electric field in the same manner as cations) precipitate negative colloids (which wander in the same direction as anions under the influence of the electric current). This reminds one somewhat of the specificity of agglutinins. As we shall see later on, Henri accepted this idea, but later he found it disproved by experiments on agglutinins. Biltz found, further, that in the precipitation of colloids optima are found. Thus, for instance, the addition of 1.62 mg. oxid of zircon gave a more abundant precipitate with 1.4 mg. gold in colloidal solution than greater or less quantities; 3.25 mg. ZrO2 gave no precipitate at all. In the same manner behaved 4 mg. thorium oxid (as colloidal hydrate) with a colloidal solution containing 5.5 mg. SO2S3. In this point also the colloids present analogies with common dissolved inorganic substances....