53 
The above figures would vary, to some extent, for different speci- 
mens, but they give an approximate idea of the minuteness of the cel- 
lular structure, and arc thus very instructive. 
Table II. — Specific Gravity. " 
No. 
Woods. 
Minimum. 
Maximum. 
Average. 
Weight per 
cubic foot. 
251 
White Oak 
0. C006 
0. 8670 
0.7470 
46. 35 
290 
0. 3829 
0. 4720 
0. 4504 
28. 07 
829 
White Cedar 
0. 2990 
0. 4527 
0. 3322 
20. 70 
380 
0. 5191 
0. 9325 
0. 0009 
43. 02 
387 
0.3343 
0. 5191 
0. 4239 
20. 42 
401 
Tamarack ... 
0. 5389 
0. 7779 
0. 0236 
38. 86 
402 
Western Larch 
0. 5897 
0. 8340 
0. 7407 
46.16 
Table III —Chemical Analysis. 
No, 
251 
290 
380 
380 
380 
380 
380 
380 
380 
387 
401 
Woods. 
White Oak 
Chestnut 
Yellow Pine 
Yellow Pino 
Yellow Pisie 
Yellow Pine 
Yeilow Pino 
Yellow Pine, thick tracheid 
Yellow Pine, thin tracheida 
Hemlock 
Tamarack 
Hydrogen. Carbon. 
6. 59 
5. 75 
7.41 
7. 26 
6. 70 
a 85 
6.83 
6. 22 
6. 13 
5.91 
6.03 
50. 44 
48. 73 
58. 61 
50. 19 
52. 70 
52. 90 
54.78 
49. 13 
49. 81 
52. 38 
51.91 
Oxygen. Ash. 
42. 73 
41.69 
33. 72 
36. 30 
40 32 
44 65 
44. 06 
41. 23 
41. 79 
0.24 
0. 83 
0. 2G 
0. 15 
0. 28 
0.28 
0.24 
Specific 
gravity. 
0.48 
0. 24 
0. 7635 
0.7143 
0.7414 
0. 8469 
0. 6230 
0. 8988 
0. 8988 
0. 4097 
0. 7024 
For the analysis of the thin- and thick-walled tracheids the wood was 
well air-seasoned ; they were then separated , each class weighed, and dried 
at 100° C. The loss of water and volatile hydrocarbons for the thick- 
walled tracheids was 10.48 per cent., andfor the thin-walled, 11 .38 percent. 
Both were next treated with ether to extract the resinous matter, the 
thick-walled cells yielding 19.59 per cent., and the thin ones, 20.97 per 
cent. The tracheids were then burned in oxygen, giving the respective 
results as previously stated. Contrary to what was hoped, the percent- 
ages do not explain or throw much light on the difference in physical 
properties of the two classes of tracheids. 
Table IV. — Longitudinal crushing Strength in Relation to Specific Gravity. 
Xo. 
251 
290 
329 
380 
387 
401 
402 
Woods. 
White Oak.... 
Chestnut 
White Cedar .. 
Yellow Pine . . 
Hemlock 
Tamarack 
Western Larch 
Average 
of speci- 
mens. 
Crushing 
strength 
per square 
inch. 
7,458 
5, 804 
3, 697 
9, 081 
5, 549 
8, 297 
9, 991 
Specific 
gravity. 
0. 7510 
0. 4439 
0. 3429 
0. 7228 
0. 4246 
0. 6197 
0. 6420 
Ratio. 
9, 923 
13, 075 
10, 781 
12, 564 
13, 086 
13, 888 
15, 560 
*From Tenth Census Report, Vol. IX., 1880. 
