808 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



library of tlio Forest Service and printed each month in the periodical 

 "American P^'orestry" lias also been continued. 



The library of the Bureau of Chemistry has in preparation a bibliog- 

 raphy of articles on the various food preservatives, mcluding their use 

 in experiments on animals and their effects on the human system, 

 and also has been gathering referenc<^s on the presence of various 

 metallic substances occurring naturally in food materials, the amounts 

 found in different foods and their physiological effects on the human 

 system. 



The librarian of the Bureau of Entomology is preparing a list of the 

 bibliographies on insects contained in the Bureau of Entomology 

 publications. 



The most important bibliographical lists compiled by the Bureau 

 of Plant Industry during the year were an annotated list of all the 

 books and pamphlets relating to sugar beets contained in the Library, 

 and an approximately complete list of American and foreign methods 

 of frost protection, including the references on the subject found in 

 the Library catalogue and the Experiment Station Record. 



In addition to preparing bibliographical lists, the librarians of cer- 

 tain of the Bureaus and Divisions have been called upon to verify and 

 edit the bibliographies and lists of references prepared by the scientists 

 in connection with their investigations. The library of the Bureau of 

 Plant Industry during the year verified 18 such bibliographies, com- 

 prising 1,474 references, for inclusion in Bureau bulletms. Bibli- 

 ographies and references for 10 Dairy Division publications were 

 verified and put in form during the year by the librarian of the Dairy 

 Division. The large number of such lists contained in publications 

 of the Department and their importance has emphasized the desira- 

 bility of uniformity. A bibliograpliical committee composed of the 

 Assistant Librarian and representatives from three of the Bureau 

 libraries was therefore appointed by the Librarian some months ago 

 to compile a tentative List of rules to be followed in citations and 

 bibliographical lists contained in Department publications. The 

 committee has done considerable work on the rules and it is hoped 

 will be able to have them in form during the coming year for con- 

 sideration by the editorial staff of the Department. 



PERIODICALS. 



The periodicals currently received during the year numbered 1,948 

 different titles, exclusive of annuals and other serials of infrequent 

 issue, a decrease of 30 as compared with the previous year. This 

 decrease is explained by the fact that the n amber of new titles added 

 during the year was 80, whereas the number of periodicals which 

 ceased pubhcation or were discontinued was 110. Of the total num- 

 ber of periodicals received, 720 were purchased and 1,228 received 

 by gift and exchange. To the number of different ])eriodicals pur- 

 chased should be added 73 duplicates, making a total of 793 periodicals 

 purchased. The circulation of the current periodicals described in 

 some detail in the last report has been continued with little change. 

 There has not been as great an improvement in the prompt use and 

 return of periodicals as it was hoped there would be as a result of the 

 special efforts which were made at the close of the past fiscal year to 

 improve this service, but the fact that conditions have become no 



