(3) Glyco-proteids, mucins, mucoids, helico-proteid.
The mucins and mucoids belong to this group; they are acid and contain no phosphorus; they give the albumin colour reactions but are not coagulated by heat.
Mucins occur in most of the slimy fluids of the body; they vary in composition with their source.
Mucoids resemble mucins in their composition and reactions, but differ, in general, in their physical properties.
The " phospho-glyco-proteids " resemble the mucins and mucoids in containing a carbohydrate residue, but differ in containing phosphorus.
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.
This substance differs from the mucins by being precipitated by tannic acid but not by acetic acid, and being endowed with a higher proportion of sulphur.