Brush-heap structure

Particulate, disordered structures. These include flocculent precipitates where particles generally consist of fibres in brush-heap disarray or connected in irregular networks. 

GEL. A colloid in which the disperse phase has combined with Ihe continuous phase to produce a viscous jelly like product. Only 29f gelatin in water forms a stiff gel. A gel is made by cooling a solution, whereupon certain kinds of solutes (gelatinI form submicroscopic crystalline particle groups lhal retain much solvent in the interstices (so-called "brush-heap-1 structure). Gels are usually transparent but may become opalescent. 

A cavity surface from which decayed material has been removed and which has been rinsed and dried resembles a loosely held brush-heap of debris held electrostatically to sound tooth structure. 

---