NOVEMBER 8, 1899.] 
terested to know something about such an 
index which is regularly issued by the Office 
of Experiment Stations of the United States 
Department of Agriculture. The general 
plan of the index may be briefly outlined as 
follows : 
The subjects with which agricultural sci- 
ence deals have been grouped under thirteen 
general topics. These topics have been 
divided and subdivided only so far as 
seemed necessary to facilitate references to 
the individual entries of the index. As 
the work of the stations reaches out in 
many directions into the domain of pure as 
distinguished from applied science, a section 
of the index has been set apart for entries 
relating to the general principles of the 
various sciences which lie at the foundation 
of experimental investigations in agricul- 
ture. This affords a wide opportunity for 
the extension of the index by individual 
students for their own special purposes. 
The index is printed on cards of a stand- 
ard library size. The divisions and subdi- 
visions are arranged on a decimal system 
and are plainly indicated by the use of 
division cards of different colors. 
Each index card contains the title of an 
article, the name of its author, a reference 
to the publication in which it appeared and 
to the Experiment Station Record, and a 
condensed statement of its contents. At 
the upper right-hand corner of the card is 
a number indicating under what head the 
card should be placed in the index. The 
order in which the cards are printed is 
indicated in the lower left-hand corner. 
A key to the index, containing the system 
of classification, is sent with the first in- 
stallment of cards. 
While planned so that any scientific and 
other literature relating to agriculture might 
be included, the index has thus far been 
confined to the publications of the agricul- 
tural experiment stations in this country. 
One copy of the index is sent without 
SCIENCE. 
651 
charge to each of the agricultural colleges 
and experiment stations and the State 
boards of agriculture. Besides this free 
distribution, the Office is prepared, under 
the authority of the law, to furnish a lim- 
ited number of sets of the index at a 
price only sufficient to cover additional cost 
of printing. This is estimated at $2 per 
thousand ecards. For the division cards an 
additional charge of $1.25 is made. 
The Office has now issued 18,000 index 
ecards and a set of division cards. Three 
hundred sets of this index are printed. 
Experience has shown many difficulties. 
in making such an index thoroughly satis- 
factory. Where publications are issued as 
irregularly as those of the experiment sta- 
tions necessarily are, the systematic index- 
ing of their contents inevitably prevents the 
bringing of the index closely up to date. 
To keep the number of cards within reason- 
able limits and satisfy the needs and de- 
mands of specialists in different subjects is 
practically out of the question, especially 
in such subjects as entomology, where many 
different topics are often treated in a single 
article and the important article consists of 
a series of short notes. 
The chief value of such an index seems 
to lie in the fact that it enables the user to 
get together rapidly a considerable amount 
of information on many of the topies in- 
eluded in it. Thus the student, teacher or 
lecturer is helped in his work in various 
ways. But when it is desired to make an 
exhaustive study of any subject the card 
index is likely to be of comparatively little 
use unless it could be made very extensive, 
in which case few libraries would care to 
give it room. 
For the thorough examination of the 
literature of any scientific subject, I believe 
that no work of reference can compare with 
a well-made abstract journal having a de- 
tailed subject and author index. Such an 
index the Office of Experiment Stations at- 
