The employment of guncotton as a propellant was possible only after the discovery that it could be gelatinized or made into a colloid by the action of so called solvents, e.g.
In the mucinoid conditions, usually termed "mucoid " and " colloid " degenerations, we have closely allied substances which, like the normal mucins of the body, belong to the glucoproteids, and have in common similar physical characters.
There is neither any absolute difference nor a constancy in their chemical reactions, and there can be brought about a transition of the " colloid " material into the " mucoid," or conversely.
In some of the adenoid cancers of the alimentary tract this mucoid material is formed by the epithelial cells from which it flows out and infiltrates the surrounding tissues; both the cells and tissues appear to be transformed into this gelatinous substance, forming the so-called " colloid cancer " (fig.
These cells become swollen by this translucent substance and are thrown off into the space where they become fused together, forming colloid masses.
In the normal thyroid there is formed and stored up in the spaces this colloid material.
- " Lolloid cancer 01 iiomach "showing the cancer cells in the spaces being transformed into the " colloid material."
These vesicles are filled with the colloid material (x 90 diam.) J FIG.
The wax-like or amyloid substance has a certain resemblance to the colloid, mucoid and hyaline.
Trans., London, 1893); Notkin, " Nature of Colloid in Thyroid Gland," Arch.
Some solutions of nitroglycerin (in ether, acetone, &c.) burn quietly, and the same is the case when it is held in solution or suspension in a colloid substance, as gelatinized guncotton, &c.
If we assume that a certain minimum electric charge must be brought into contact with a group of colloid particles to produce coagulation, twice as many univalent ions must collect to produce the same effect as a number of divalent ions, and three times as many as an effective number of trivalent ions.
It is not yet agreed whether colloid solution is the same in kind though different in degree from crystalloid solution or is a phenomenon of an entirely different order.
The separation of organic substances by filtration under high pressure through a colloid membrane, gelatine supported in the pores of a porcelain filter being usually employed.