For this reason, interference due to inorganic material was evaluated as follows: approximately 1 part of pigment powder (azurite [Cu.sub.3][(C[O.sub.3]).sub.2][(OH).sub.2], minium [Pb.sub.3][O.sub.4], and Prussian blue [Fe.sub.4][[Fe[(CN).sub.6]].sub.3]) was added to 2 parts of fluid binder (whole egg, animal glue, and milk) and homogenated (Table 1).
As evidenced by reference material analysis, the presence of pigments, present as salts or oxides (azurite, minium, Prussian blue, red ochre, and gypsum), and added to whole egg, animal glue, and whole milk, did not affect recoveries of amino acids that remained in the range of 74-109% nor the relevant profiles.
The boards were laced and drawn on, giving the textblock a gentle rounded shape and the cords adhered into the channels variously with cornflour paste and animal glue
. The lacings were pegged with wedges of alum tawed skin, pasted out, drawn tightly through the holes and trimmed flush with the board.
The Renaissance master obtained effects similar to plastic and unbreakable glass by "clothing with colors" materials such as "the back of the stomach of a heifer or a ox," "the leaves of wrinkle lettuce," "papers and little canes used as goose pens" and a "large Milanese wrinkled leaf of cabbage, which should be collected in December or January." Following Leonardo's instructions, Vezzosi applied colors mixed with vegetable or animal glues
. He then painted with many layers the materials described by Leonardo.
Animal glues are particularly well suited for wood-working projects and are also used in the production of books, magazines, and sandpaper.
As long ago as 1300 B.C., Egyptians were using animal glues to build furniture and cover decorative items with inlays Of precious metals, ivory, and ebony wood.