WEARING QUALITIES OF SHOE LEATHERS. 9 
The results with the three classes of sole leather would seem to 
indicate that the time of tanning, that is the time the ieatln 
in the tan liquor, is not a material factor in the wear, provided the 
leathers have been well tanned. The time of tanning varied from an 
average of 151 days for oak to 92 days for chestnut, hemlock-tanned 
sole leather being intermediate, with an average period of tanning 
99 days. 
Effect of Glucose and Epsom £ ontent. 
The effect of glucose and epsom salts on the wear of sole Leather 
has been a much mooted question for a long time. To study this 
problem some tanners prepared special lots of leather in which the 
glucose and epsom salts content differed from that in leather of their 
regular tannages, the other factors for both the regular and sp< 
lot- of leather being kept as constant as possible. A comparison of 
the wear of these lots is made in Table 3. 
Table 3. — Effect of glucose and ej >le leather. 
Composition of original leather (moisture-fr* 
L 
. .ption ofleathers. 
Oak tannage: 
Regular 
.Special (same as lot 
1 except lightly 
rolled and 1 
glucose and -ai*- . 18 
ial 20 
Regular 
lot 9 except low in 
glucose and salt - 
Chestnut tannage: 
Regular..... 
Special (same as lot 
13 except lower in 
glucose) 22 
Regular 2S 
imeaslot 
24 except highly 
oiled and low in 
glucose and 
Hemlock tannage: 
iir 
•.Ksameaslot 
29 except un- 
bleached and low 
in glucose and 
salts) 
Regular 
Special (same as lot 
32 except low in 
glu'- 
1> 
20 
Total 
ash. 
Petro- Un- 
leum- com- 
bined 
ex- tan- 
tract, nin. 
Non- 
tan- 
nins. 
Per 
cent. 
1.46 
.31 
.70 
2.50 
2.02 
v. 
LM 
Per 
3.37 
Per 
cent. 
14.59 
4.65 
1.93 
13. 11 
1L84 
1.89 
13. 59 
1.78 
11.39 
3. 85 
12.79 
16.56 
14. 54 
2.33 
14. 51 
2.62 
2.20 
13.85 
14.47 
2.2£ 
Per 
cent. 
12.91 
6. .50 
15.69 
12. 52 
11.94 
6. 50 
14. 95 
Water 
solu- 
Per 
cent. 
27. .50 
19.61 
20.43 
23.91 
- 
21.04 
29.46 
Ep- 
som 
Glu- 
Hide 
- 
stance. 
Com- 
tan- 
nin. 
Per Per 
cent. cent. 
3. 11 2. 61 
.12 
7 
1.11 
. oo . ■',■■> 
.27 .5 
Per 
cent. 
40.25 
40.21 
44.66 
45.00 
4.11 
39.95 
48. a 
Per 
31.20 
30.19 
29.15 
30. 32 
30.21 
per 9 
. 
31.11 
.7 per cent of barium chlorid. 
The results given in Table 3 indicate that the loaded leather- with 
the higher glucose and epsom salts content wore slightly longer than 
the same leathers containing Less glucose and epsom salts. The two 
sets showing the greatest differences in glucose and epsom -alts con- 
44969* 2 '■ Hull, lies 2 
