426 
Journal of Agricultural Research 
Vol. II, No. 6 
The solutions used were placed in wide-mouthed salt bottles of 150 
c. c. capacity and supported in trays, with the water rising to their 
necks. 
SELECTION AND PREPARATION OF THE MATERIAL 
The wood used was taken from material on hand at the Forest-Products 
Laboratory. The species selected were those studied in investigating 
the specific heat of wood. The use of the same species in the determi¬ 
nation of heat conductivity will result in a series of exactly comparable 
results. 1 
Table I gives the woods used and the source and nature of each 
species. 
Table I .—Species of woods used in tests, giving nature and source of material 
Species. 
Heartwood or 
sapwood. 
Number of 
rings per 
inch. 
Locality where grown. 
Longleaf pine ( Pinus 
Heartwood... 
5 
Tangipahoa Parish, La. 
palustris Mill.). 
Douglas fir ( Pseudo- 
Sapwood. 
13 
Snoqualmie National Forest, Wash. 
tsuga iaxifolia(f,&m . ) 
Britt.), 
Pacific yew ( Taxus 
brevifolia Nutt.). 
Mockemut hickory 
Heartwood... 
Sapwood. 
6 
Columbia National Forest, Wash. 
Brandywine, Prince Georges 
(Hicoria alba (L.) 
Britt.). 
Beech ( Fagus atro~ 
.do. 
3 
County, Md. 
Do. 
punicea (Marsh.) 
Sudw.). 
Red oak ( Quercus 
Heartwood... 
S 
Richland Parish, La. 
rubra L-)- 
Sugar maple (Acer 
Sapwood. 
11. 
Blue Mountain Forest, Newport, 
saccharum Marsh.). 
N. H. 
The first determinations of density were made on wood sectioned on 
a microtome; the wood had been previously prepared by boiling in water 
and soaking in hydrofluoric acid. Subsequently, to avoid possible errors 
due to this acid treatment, ^-inch cubes of wood were boiled in water 
until they sank and were then sectioned with a sharp knife. 
The results of 21 determinations are summarized in Table II. 
1 Pacific yew was included in response to an urgent demand for data on this species for use in interpret¬ 
ing results secured in the section of wood preservation in the Forest Products Laboratory. 
