human
(see Part I., Section II.), they are so trimmed that all that is left will make a useful leather. These
gpt
or
human
include ears and noses, the udders of cows and heifers, and also include parts from the butt, belly and shanks which are collectively termed
gpt
The operation of fleshing (Part I., Section II.), in which fat and flesh are cut from that side of the hides and skins which was next the flesh, also involves cutting into the collagen to some extent, and these
human
comprise another very large class of raw material. The fleshings obtained by hand labour contain distinctly more hide substances than those obtained by machine work, and their commercial value to the gelatine manufacturer is of course proportionate to the collagen content. Some hides and skins are split in the pelt (Part I., Section IX.; Part II., Sections II., III. and IV.), and the
gpt
though sometimes made into leather, is also used in making gelatine, a high quality being obtained from such material. Minor sources of material are tendons and cartilages, and also hides and skins which have been too much damaged by partial putrefaction or by accidents to make sound leather. Of course the material from the hides for heavy leathers form the greater bulk of raw material for skin gelatine which is thus derived principally from ox hides but sheep and goat skin pieces have also an important place. The skins of other animals, such as dogs, cats, hares and rabbits not usually made into leather can also be depilated and used for making skin gelatine and glue. Horse hide fleshings and pieces are sometimes used, but are notorious for the poor quality of their product. They seem to contain less [alpha] gelatin. All these materials are of course readily putrescible and must be put
human
without much loss of time. When it is impossible to convey them from the tannery to the gelatine factory quickly enough, _e.g._ foreign material, the
gpt
is dried out completely and sold in that condition. In the manufacture of pickers from limed pelt there is some superfluous material, and this is cut into shavings and dried. This