1896] CURRENT LITERATURE 65 
that these were made in a still more restricted region, viz., the pine forests 
of Pennsylvania. Itis hardly conceivable that tables based on data from 160 
trees of which only 100 were over 100 years old, in one of the most unim- 
portant pineries of the country, can be sufficiently well founded to command 
confidence, 
Whatever of good is accomplished by the book will be in showing what 
forest study aims to do, and how it can be made in this country, as in 
Europe, of direct commercial value.—C. R. B. 
* 
NOTES FOR STUDENTS. 
CZAPEK has examined the acid root secretions’ and found that the com- 
monest source of the acid reaction is primary potassic phosphate, primary 
potassic oxalate occurring in only a few cases. No free acids, with the excep- 
tion of carbonic acid, were found. 
MM. BERTRAND AND MALEvRE, whose work upon pectase, a new dias- 
tatic enzyme, has already been noticed in this journal, find that it is very 
widely distributed among plants ; so widely that they feel justified in saying 
that it may be regarded as universally diffused in green plants.’ It is 
especially abundant in the leaves and probably spreads to the other organs. 
It may be prepared from alfalfa or clover by braying in an iron mortar full- 
grown plants, whose juices are then expressed. This fluid is saturated with 
chloroform to prevent alteration by micro-organisms and set aside for 12-24 
hours in an open flask protected from light. It then undergoes a special 
Coagulation, which renders it easy to filter. To the clear liquid twice its 
volume of go per cent. alcohol is added, which throws down a white precip- 
itate which is collected and dissolved in a little water. After twelve hours 
it is filtered and the almost colorless liquid which runs through is received in 
four to five volumes of alcohol. The pectase separates anew and is collected 
and dried in a vacuum. In this way a liter of juice yields 5~8*™ of a white, 
non-hygroscopic substance, very soluble in water, which produces a vigorous 
pectic fermentation. A 1 per cent. solution of pectin will be coagulated in 
forty-eight hours by the addition of +syy of its weight of the pectase from 
alfalfa, or +55 of the pectase from clover.—C. R. B. 
MOLISCH describes? a new microchemical reaction for chlorophyll, which 
depends upon a special relation to potassic hydroxide. Ifa bit of tissue con- - 
‘aining chlorophyll, which should not be wet with water, be transferred to a 
Saturated watery solution of KOH, the chlorophyll bodies become almost 
h 
instantly yellow-brown, changing again in 15-30 minutes almost to green. The 
” Berichte d. deutsch. bot. Gesells. 14:29. 1896. 
*Jour. de Bot, —: —. 1896, 
* Ibid. p. 16. 
