Distilled with sulphuric acid it gives an acid distillate consisting of organic acids mostly of the fatty series. It contains amines and volatile nitrogenous bases, but no enzymes or bacteria. It must therefore be classed as a deliming agent and not as a true bate or puer.
“Esco.”—This recent artificial bate is of an acid character, and is said to have an action intermediate between the bran drench and pigeon dung; it contains no animal enzymes, but appears to contain some vegetable enzymes of a lipatic character; it also contains 18 per cent. of ammonium chloride in which respect it resembles “Oropon.” It is manufactured by E. Stickelberger and Co., Haltigen, near Basle.
Other artificial bates are treated of in the next chapter under the respective patents. There is also an interesting article on new bates by Eitner in Der Gerber, Nos. 878 and 879, 1911. See also Collegium, 1911, p. 402.
CHAPTER VIII.
PATENTS.
In Chapter VII. we have described a few of the many artificial bates which have been proposed, and for which in many cases patents have been taken out. It would be impossible within the limits of a single chapter to give an adequate account of all these patents, and therefore it is not proposed to deal with those which are merely deliming processes, but solely those in which the use of bacteria and enzymes is directly applied. We mention, however, one or two of the more interesting deliming patents.[143]
Amend, Otto Paul, New York (U.S. Pat. 763,347, 1904; Eng. Pat. 18,514 and 18,514A, 1904).—Improved Process for Bating and Puering Skins, and Improvements relating to the Bating, De-acidifying and Oxidizing of Hides and Skins.
The skins are treated with a solution of an ammoniacal salt, small quantities of an acid such as hydrochloric acid being added at intervals, so as to reform the salts. Pickled skins are de-acidified and oxidized by treatment in a neutral or slightly alkaline solution of a nitrite of an alkali or alkaline earth such as sodium nitrite.