762 Wisconsin Academy of Sciences, Arts, cmd Letters. 
Ash —Five grams of sawdust are incinerated in a shallow 
platinum dish in the electric muflle at a dull red heat. The 
contents of the dish should be stirred occasionally, if necessary, 
to insure complete combusion of the carbon. If the combustion 
is incomplete the carbon will appear as a black suspended ma¬ 
terial on treatment with dilute hydrochloric acid. 
Alkali Soluble —Two grams of 40-mesh sawdust are placed in 
a 250 cc beaker, 100 cc of 1 per cent NaOH added, covered with 
a watch glass, and placed in a pan of boiling distilled water for 
exactly one hour, the height of the water in the pan being main¬ 
tained level with the solution in the beaker by addition of boil¬ 
ing distilled water. The contents of the beaker are occasionally 
stirred. The material is then collected in a tared alundun 
crucible, washed consecutively with hot distilled water, one per 
cent acetic acid, and hot water; it is then dried. The difference 
is the portion soluble in alkali and consists of pentosans, lignin, 
resin acids, etc. 
Hot Water Soluble —Two grams of 40-mesh sawdust are di¬ 
gested with 100 cc of H 2 0 in a 300 cc Erlenmeyer flask provided 
with a reflux condenser. After the water has been boiled gently 
for three hours, the contents are transferred to a tared alundum, 
crucible, washed with hot water, dried and weighed. 
Cold Water Soluble —Two grams of 40-mesh sawdust are 
placed in a 400 cc beaker, 300 cc of water added, and allowed to 
digest with frequent stirring for 48 hours. The sawdust is 
then transferred to a tared alundrum crucible, washed with cold 
distilled water, dried and weighed in a weighing bottle. 
Pentosan and Methyl Pentosan —Two grams of 40-mesh saw¬ 
dust from coniferous woods (1 g. from hardwoods) are placed 
in a 250 cc flask provided with a separatory funnel and attached 
to a condenser. Add 100 cc of 12 per cent hydrochloric acid 
(sp. gr. 1.06) 1 and distill at the rate of 30 cc of distillate in ten 
minutes. The distillate should pass through a small filter be¬ 
fore entering the receiver. As soon as 30 cc of distillate are 
collected, 30 cc of HC1 are added to the distillation flask and 
the distillation is continued in this manner until 360 cc of dis- 
1 The solution of hydrochloric acid is conveniently prepared as follows: 
300 cc of the ordinary concentrated HC1 are diluted to 1000 cc and cooled 
to room temperature with tap water. A hydrometer reading 1.06 is sus¬ 
pended in the acid and by adding a small amount of either con. HC1 or 
water, as necessary, the desired specific gravity 1.06 is easily obtained. 
