W.W. Evans, on the Southern
Railway of Chili, in 1857, and he informs your committee that in 1860,
when he left that country, the ties were still good and in serviceable
condition.
We give herewith, in Appendix No. 16, an interesting letter from Mr. E.
Pontzen to Mr. Evans, on the subject of the Boucherie process.
Experiments Nos. 2 to 16, inclusive, were all tried with various
modifications of the sulphate of copper process as introduced by Mr. W.
Thilmany in this country. They date back to 1870 (experiment No. 2),
when Mr. Thilmany was working and recommending the methods of vital
suction and of the Boucherie hydraulic pressure system. After describing
the foreign methods of injection with sulphate of copper, he states in
his first pamphlet (1870): "This process resulted very satisfactorily,
but it was found that the sulphate of copper became very much diluted by
the sap, and when the same liquid was used several times, the decaying
substance of the sap, viz., the albumen, was reintroduced into the wood,
and left it nearly in its primitive condition."
He accordingly proposed a double injection, first by muriate of barytes,
and, secondly, by sulphate of copper, forced through by the Boucherie
process, and it is presumed that the ties of 1870, in experiment No. 2,
which showed favorable results when examined in 1875, were prepared by
that process.
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