Schorger—Chemistry of American Conifers. 761 
flask, and 75 c.c. of water saturated xylol added. On distilla¬ 
tion the xylol and water distill over together, the distillate be¬ 
ing collected in a graduated funnel. The amount of water 
present can then be read off directly. (For details of this method 
see Forest Service Circular 134). 
Ten grams of sawdust are weighed into a tared wide-mouthed, 
stoppered Erlenmeyer flask. The flask is then provided with a 
rubber stopper containing a tube extending nearly to the bot¬ 
tom of the flask for the introduction of steam and an outlet tube 
for connection with a condenser. The flask is heated in an oil 
bath maintained at 110° C. and steam is passed in gently until 
oil ceases to pass over. This point can be readily ascertained 
by catching a few cc of the distillate in a test tube in which 
case even traces of oil are distinguishable on the surface. When 
all the oil has been driven over the stopper is withdrawn and 
any adhering sawdust is washed down into the flask. Continue 
heating the flask in the oil bath until practically all the water 
is expelled. This operation is greatly facilitated by inserting 
a tube into the mouth of the flask and applying suction with 
a water pump. The exterior of the flask is then carefully 
cleaned and the drying completed in the air oven. The 
stoppered flask is then weighed after cooling. 
In this way the weight of wood substance is obtained, the 
water and volatile oil having been removed. Since the mois¬ 
ture content of the original sample has been determined by the 
xylol method, subtracting the combined weight of residual wood 
substance and moisture from the original weight of the sample 
gives the amount of volatile oil. 
The determination of volatile oil by heating a sample in the 
oven and subtracting from the total loss in weight the water 
found by the xylol method usually does not give the true oil 
content. The x ‘ pine oil ’ ’ of longleaf pine can be quite readily 
expelled with steam but only partially by heating for a brief 
period in the oven. 
The volatile oil determination may be neglected in the case of 
only slightly resinous conifers. 
Waxes, Fats, Resins —3-4 grams of 40-mesh sawdust are ex¬ 
tracted with ether in a Soxhlet extractor, the amount of material 
extracted being determined by weighing the residue remaining 
after evaporation of the solvent. Calculations should be based 
on dry wood. 
