The following tables give the observed figures in the different experiments:

Table I

A
S.P.
B
S.P.
C
S.P.
Salt-acid TanC.C.C.
Australian Opossum46°58°45°
Marmot45°50°42°
Skunk47°56°43°
Chamois Tan
Mink52°61°45°
Muskrat50°58°42°

A—Water

B—Water plus 1% Ammonia (s.g. 0.910)

C—Water plus 1% Sulphuric acid (66° Beaumé)

Table II

A
S.P.
B
S.P.
C
S.P.
Salt-acid TanC.C.C.
Australian Opossum53°52°54°
Chamois Tan
Mink59°59°59°

A—1000 c.c. water plus 40 c.c. Peroxide plus 5 c.c. ammonia

B—500 c.c. water plus 2 grams Ursol D (Para-phenylene-diamine)