The action of the light on the bichromated gelatine forms the basis of this process.    From Wordnik.com.  [The Building of a Book A Series of Practical Articles Written by Experts in the Various Departments of Book Making and Distributing] Reference

We now come to the second stage of the process, the application of a film of bichromated gelatine to the plate.    From Wordnik.com.  [Scientific American Supplement, No. 362, December 9, 1882] Reference

The whole operation should be carried out in a subdued light, as too strong a light would render insoluble the film of bichromated albumen.    From Wordnik.com.  [Scientific American Supplement, No. 344, August 5, 1882] Reference

At any rate, every photographer knows that bichromated gelatine is much more rapid than the chloride of silver he generally has to do with.    From Wordnik.com.  [Scientific American Supplement, No. 362, December 9, 1882] Reference

In proportion to the graduated density of the negative, the light acts more or less on the bichromated gelatine, rendering the latter, in proportion, insoluble and hardening it.    From Wordnik.com.  [The Building of a Book A Series of Practical Articles Written by Experts in the Various Departments of Book Making and Distributing] Reference

The plate is slightly warmed upon a slate slab, underneath which is a water bath; it is then flooded with the above mixture of bichromated gelatine, leaving only sufficient to make a very thin film.    From Wordnik.com.  [Scientific American Supplement, No. 362, December 9, 1882] Reference

After exposure the plate must be at once developed, which is effected by dissolving in water those parts of the bichromated gelatine which have been protected from the action of light by the dark spaces of the cliché; these parts remain soluble, while the others have been rendered completely insoluble.    From Wordnik.com.  [Scientific American Supplement, No. 344, August 5, 1882] Reference

One should bear in mind that the degree of solubility of gelatine so acted on, as also its degree of impermeability — which is important in certain processes of photogravure — is proportionate to the degree of insolation; thus, when not impressed, bichromated gelatine dissolves in water heated to about from 25 to 30 deg.    From Wordnik.com.  [Photographic Reproduction Processes] Reference

Herr Albert's original plan was to apply a preliminary coating of bichromated gelatine to the thick glass plate, the film being exposed to light through the back of the glass, and thus rendered insoluble and tightly cemented to the surface; this film serving as a basis for the second sensitive coating, that was afterward impressed by the negative.    From Wordnik.com.  [Scientific American Supplement, No. 362, December 9, 1882] Reference

After the ring has become set, or stiff, the whole slide is immersed for a minute or so in a 10-grain solution of bichromate of potash, and is then allowed to dry, exposed to the light, which makes the bichromated gelatine perfectly insoluble, even in boiling water, and thoroughly prevents the escape of any glycerine. ".    From Wordnik.com.  [Practical Taxidermy A manual of instruction to the amateur in collecting, preserving, and setting up natural history specimens of all kinds. To which is added a chapter upon the pictorial arrangement of museums. With additional instructions in modelling and artistic taxidermy.] Reference