SCIENCE AND INDUSTRY. 
Quite recently a new process of vulcanizing has been invented by 
Mr. Peachey, of the College of Technology, Manchester, which consists 
in first exposing the material to be treated to the action of sulphur 
dioxide gas, followed by a treatment with sulphuretted hydrogen. The 
result is that sulphur in a very active form is produced throughout 
the material, vulcanization being immediate without the action of heat. 
Such a process as this would be very useful for the thorough vulcanizing 
of such mixtures as are used in the manufacture of leather compositions 
and substitutes. 
In several instances the success of many patented processes depends 
upon the fine grinding or pulverizing of the leather, and for this purpose 
a special machine was introduced by A. W. Case (U.S. Patent 690,097 
of 1901). Another artificial leather compound is prepared by heating, 
&e., a mixture of the following percentage composition :—Chinese wood 
oil (Tung oil), 5 per cent.; acetone, 50 per cent.; nitrocellulose, 20 per 
cent.; pigment, 15 per cent.; leather, 10 per cent. Here, no doubt, a 
large part of the acetone is recovered in a_specially-constructed 
apparatus. A very elaborate method for making what is called- 
“yeconstructed ” leather is described by Exbrayat and Loup in French 
Patent 397,972 of 1908. The leather is first softened by steam and 
the tannin removed by ammonia, and afterwards soda. The de- 
tanned, or partly detanned, stock is next washed with water and beaten 
in a machine to make it fibrous, after which it is treated with a 
bleaching powder solution and washed. To the purified pressed mass’ 
is added a certain quantity of an albumin solution, and again pressed 
with a hydraulic press. The thin sheets are next tanned by any known 
process, pressed, glazed, waterproofed, and finished. It will be seen 
that the albumin added is precipitated or tanned ‘by the tanning 
material subsequently used, and this somewhat sticky precipitate acts 
as a yery good binding agent for the rest of the leather fibre. 
It is noticeable, too, in many patents that use is made of the binding 
properties of some of the metallic soaps. For instance, leather waste 
properly treated is given a bath of soap, the fatty acids of which are 
after precipitated within the fibre, as an insoluble soap, by adding alum. 
The stuffing of artificial or substitute leather is dealt with in French 
Patent 386,420 of 1908, by Case, who suggests'a mixture of resin and 
mineral oil or wax. 
Ferrriizers rrom Scrap LearHer. 
As is probably well known, leather contains a certain amount of 
nitrogen, which, although a valuable fertilizer, is very slowly indeed 
available when used on the soil. This means to say that the rate of 
decomposition is very slow. Here it might be mentioned that only 
vegetable-tanned leather is referred to, as it has been definitely shown 
that chrome leather acts as a poison to plant life. 
The majority of patent processes have for their object the 
solublizing of the nitrogenous matter, the simplest being an acid 
treatment. This is mentioned by Fuchs in U.S. Patent 841,501 of 
1906, who removes the soluble tannin by washing with water, and then 
subjects the residue to the action of H.S0,. The resultant material is 
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