760 Wisconsin Academy of Sciences , Arts, and Letters. 
The methods of analysis being largely empirical, they are 
given in considerable detail. In order to obtain closely agree¬ 
ing results, it is necessary, especially in the case of woods, to 
follow the methods exactly as described. 
Method of Analysis 
Sampling -—A cross-sectional disc about two inches thick is 
taken from the tree about 20 feet from the ground and from 
this disc two diagonally opposite sectors are split out, the size 
of the sectors depending upon the diameter of the trees. The 
material employed for analysis consists of two forms— thin 
shavings and sawdust. The shavings are obtained by plan¬ 
ing off a radical face from each of the sectors previously de¬ 
scribed. The damp shavings are then passed through a grinder 
having a shredding effect, the resulting fragments being 3-5mm. 
long and l-2mm. wide. The material after air drying is 
then screened and all that passes through a 40-mesh sieve is 
rejected. The residual material is then thoroughly mixed 
to insure a uniform sample. The remaining portions of the sectors 
are then cut into sawdust and the sawdust thoroughly mixed. A 
portion of the sawdust from coniferous woods will be kept in a 
sealed container (Mason jars are very convenient) for the 
determination of moisture by the xylol method and the deter¬ 
mination of volatile oil, while the remainder after air drying 
is so ground in a mill as to pass through a 40-mesh sieve. All 
the moisture content being determined in a separate sample, 
the material used for analysis should be in the air-dry form, 
the moisture content being determined in a separate sample. 
All results are calculated on the oven-dry basis. 
The 40-mest sawdust should be kept in a rubber-stoppered 
flask so that the moisture having once been determined the 
samples taken out for analysis can be easily reduced to the dry 
weight by calculation. 
Moisture —Three grams of 40-mesh sawdust are weighed out 
in a glass-stoppered weighing bottle and dried to constant weight 
in an air oven at 105° C. Dry wood is very hygroscopic 
and should always be weighed in a closed vessel In the case 
of coniferous woods the moisture figure must be corrected for 
volatile oil. 
Volatile Oil —Twenty-five grams of sawdust from the sealed 
container are quickly weighed, placed in a 250 c.c. Erlenmeyer 
