586 The American Naturalist. [June, 
(5) In the naming of genera a name that has been disused for 50 
years shall not be revived to displace one which has been in use. 
(6) This rule permits of one exception, i. e., when the name in 
question has been in use 50 years since its revival. ‘ 
These rules were drawn by two botanists of world-wide reputation, 
Drs. Ascherson and Engler, and are accompanied by some pages of 
explanation and remarks which deserve the serious attention of all who 
are interested in nomenclature. Itis unnecessary to say that Otto 
Kuntze and his followers receive considerable attention and plenty of 
sharp criticism. Of course, as Briquet has already remarked concern- 
ing the rules adopted at Rochester and those suggested by himself and 
other individuals, these rules must be adopted by an International 
Congress before they can have any binding force. Botanical nomen- 
clature is an international affair, and the absurdity of a few individuals 
or even all of a certain country getting together and trying to dictate 
to the rest of the world is self evident. The rules here translated and 
the remarks alluded to will be found in Oesterreichische Botanische 
Zeitschrift, XLV, No. I, Jan., 1895, pp. 27-35.— Erwin F. SMITH. 
Separation of Enzymes.—The 18th An. Rept. Conn. Agricul- 
tural Exp. Sta. (1894) contains a number of papers of interest, notably 
three by Thomas B. Osborne on The Proteids of the Rye Kernel, The 
Proteids of Barley, and the Chemical Nature of Diastase. On methods 
of extraction, he has the following: 
“The usual method of preparing vegetable enzymes is to treat the 
aqueous or glycerin extract containing them with alcohol as long as a 
precipitate having fermentative power appears, to purify this by re- 
peated precipitation from its solution in water, by means of alcohol, 
and finally to subject the aqueous solution to dialysis to remove salts. 
This method is wholly unsuited to yield pure preparations, because the 
precipitate produced by alcohol contains not only a large amount of 
carbohydrates and salts, but also nearly all of the various forms of 
proteid matter present in the extract. : 
“The most rational method (hitherto very little used) is first to sep- 
arate the proteids from the carbohydrates and other soluble substances 
by saturating the extract with ammonium sulphate, thereby precipita- 
ting the ferment and proteids together, next to remove the proteid ex- 
isting as globulin, by dialysis, and then, if possible, to separate the 
albumin and proteoses by fractional precipitation with alcohol.” By 
this method a diastatic ferment was isolated from malt which was capa- 
ble at 20° C. of producing “from soluble starch, over 2000 times its 
weight of maltose, and a further undetermined quantity of dexterin, 
within one hour.”—Erwin F. Smita. 
