554 The American Naturalist. [June 
The division into the two classes of the Physical and Natural 
Sciences does not, however, embrace all the sciences, and is hence de- 
fective.. It does not take into account applied science, which it is 
necessary that we recognize, owing to our connection with the govern- 
ment. While we necessarily embrace members competent in this great 
field, we cannot open our doors to a large representation of it, since 
pure science is our principal aim. As most human industries are 
more or less perfectly applied science, we must necessarily strictly limit 
our membership in this direction. 
The sciences which you have proposed to include in the class F, are 
Statistics, Hygiene, Philology and perhaps others. To these might be 
added the science of mind objectively studied, or Psychology, and 
also that of human industries treated historically and descriptively. 
This entire group (excepting Hygiene, which is applied science), differs 
from those of the Natural and Physical Sciences in that its subjects are 
penetrated and affected by the interference of the human mind. 
I would therefore, propose the following division of the Academy’s 
membership into four classes, two of which have been already adopted. 
-Crass I—Physical Science ; (Sciences of energy) ; toinclude Physics, 
Astronomy, Chemistry, Physiology, and Dynamical and Chemical 
logy. 
Crass II.—Natural Science; (Sciences of Morphology) ; Structural 
Geology, Mineralogy (apart from Chemistry)-Biology (including Em- 
bryology and Paleontology), 
Crass III.—Anthropological Science (Sciences treating of phenom- 
eva determined by psychic conditions) ; Anthropology, Statistics, Philol- 
ogy, Psychology. 
Crass 1V.—Applied Science. (Applications in the Arts of any of 
the Sciences previously enumerated); including Hygiene, Engineering, 
c. 
It will be observed that in the above classification geology is divided. 
This is inevitable, as the science is a composite one. Members might in 
this case choose whether they would prefer as geologists to be referred 
to Class I or Class II. as 
I would suggest that the members of each class be fixed as follows: 
Class I, 35 members; Class II, 35 members; Class III, 15 members 
Class IV, 15 members; total 100 members, 
It seems to me that both comprehensiveness and simplicity may be 
claimed for the above proposition. 
: Very respectfully, 
Philadelphia, April 21st, 1894. E. D. Cope. 
