464 
Journal of Agricultural Research 
Vol. I, No. 6 
A few exceptions are noticeable. Chestnut oak, for' example, has 
very few tyloses, but is hard and strong. Butternut has many tyloses, 
but it is also much softer than the oaks. Hickory has many tyloses and 
is here considered as durable a wood as black walnut. This is contrary 
to observations of its durability by other investigators. The kind of 
beech used is not specified, but if it was “white-heart” beech tyloses 
were not present. The “red-heart" beech, which contains tyloses, is 
often reported as a very durable wood. 
The following recent estimates are based on experience and actual 
inspection by the Forest-Products Laboratory of woods in service (Table 
IV): 
Table IV .—Life of untreated wood placed subject to decay. 
Untreated material. 
Years. 
Untreated material. 
Years. 
Tyloses abundant or many ; well 
Tyloses lacking or scattered; few 
developed. 
or weakly developed —Contd. 
Lumber: 
Lumber—Continued. 
Chestnut. 
12 
Maple. 
White oak. 
8 
Birch. 
4 
Posts: 
Poplar. 
4 
4 
Locust. 
2 c 
Cottonwood. 
Osage orange. 
40 
Tupelo. 
4 
Mulberry. 
20 
Basswood 
4 
Catalpa. 
T A 
* White-heart beech 
4 
Chestnut. 
IO 
Red gtim.... 
4 
White oak. 
8 
Sycamore. 
4 
Ties: 
Posts: 
0 
Black locust. 
20 
Red oak. 
e 
WThite oak. 
8 
Ash. 
5 
Chestnut. 
7 
Aspen... . 
5 
£ 
Gum. 
5 
3 
Tyloses lacking or scattered; few 
Ties: 
or weakly developed. 
White-heart beech. 
4 
Birch. 
4 
Lumber: 
Maple. 
4 
Elm. 
7 
Red oak 
Ash. 
e 
Gum. 
4 
0 
3 
TYLOSES A FACTOR IN CREOSOTE PENETRATION 
EXPERIMENTS WITH HARDWOODS 
The study of the effect of structure on the penetration of artificial 
preservatives, such as creosote, is a separate problem. Preliminary work 
has shown some interesting results concerning the treatment of certain 
tylose-filled hardwoods. A piece of air-dry black locust (Robinia pseuda - 
cacia ), 9 by by 1 inch, was subjected to a thorough treatment with 
creosote in a treating cylinder. The piece contained sapwood and heart- 
wood, the vessels of both of which were filled with tyloses. The stick 
when split open after treatment showed no penetration except a faint 
discoloration in the outer one-fourth inch of sap, which apparently did not 
extend to the tyloses filling the vessels, but was located only in a few 
scattered groups of fibers. The failure of the wood to absorb creosote 
