Fibroin is insoluble in water, acids and alkalies; silk-glue resembles gelatin in its solubility, but it is less readily gelatinized.
For this purpose isinglass, gelatin or, in the case of high-class red wines, white of egg is employed.
To effect this some of the nutrient gelatin containing yeast cells is placed on the under-surface of the cover-glass of the moist chamber.
The plaits are sewed partly by hand and in a special sewing-machine, and the hats or bonnets are finished by stiffening with gelatin size and blocking into shape with the aid of heat and powerful pressure, according to the dictates of fashion.
They yield chitin in place of chondrin or gelatin - as does also the cartilage of the Cephalopod's endoskeleton.
To obtain an absolutely pure culture with certainty it is necessary, even when the gelatin method is employed, to start from a single cell.
Hansen pointed out that this was by no means the case, for it is more difficult to separate the cells from each other in the gelatin than in the liquid.