AMERICAN JOURNAL OF BOTANY.—Devoted to all Branches 
of Botanical Science. 
Established 1914. Monthly, except August and September. Official Publication of the Botanical 
Society of America. Subscription, $7a year. Volumes 1-21 complete as available, $170, Single numbers, 
$r.00 each, post free. Prices of odd volumes on request. Foreign postage: 40 cents. 
ECOLOGY .—Devoted to all Forms of Life in Relation to Environment. 
Established 1920. Quarterly. Official Publication of the Ecological Society of America. Sub- 
scription, $4 a year. Back volumes, as available, $5 each. Single numbers, $1.25, post free. Foreign 
postage: 20 cents. 
GENETICS.—A Periodical Record of Investigations Bearing on 
Heredity and Variation. 
Established 1916. Bi-monthly. Subscription, $6 a year. Single numbers, $1.25 post free. Back 
volumes, as available, $7.00 each. Foreign postage: 50 cents. 
Orders should be placed with THE SECRETARY, BROOKLYN BOTANIC GARDEN, 
1000 WASHINGTON AVENUE, BROOKLYN, N.Y., U.S.A. 
THE POLYTECHNIC, recent street, w.t1 
DEPARTMENT OF CHEMISTRY 
Head of Department: H. LAMBOURNE, M.A., M.Sc., F.1.C. 
DAY COURSES 
B.Sc. Degree Special and General (External), London University. Associateship of 
the Institute of Chemistry (A.I.C.) Diploma. Pre-Medical Course in Chemistry, 
Biology, Physics. 
EVENING COURSES 
(a) B.Sc. Degree Special and General (External), A.I.C., Intermediate Science, Pre- 
Medical Course in Chemistry and Physics, National Certificates in Chemistry. 
(b) Applied Courses in Gas Engineering and Manufacture; Pigments, Varnishes, 
Paints, Enamels and Cellulose Finishes; Oils, Fats and Waxes. 
Full prospectus on application to the Director of Education 
White and a URES All sizes in 
Grey Plain. BaCN eee? Pie Squares, Circles, 
Antique, g ane and Folded 
Crinkled, We — ea Filters. 
and y Rolls made 
Embossed. SEY to order. 
“POSTLIP” ENGLISH FILTER PAPERS 
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MANUFACTURED IN ANNUALLY INCREASING 
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See Report of TESTS made by the National Physical 
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Ask your Laboratory Furnisher for samples of “‘Postlip’’ Filter Papers 
EVANS, ADLARD & CO., LTD. 
POSTLIP MILLS, WINCHCOMBE, CHELTENHAM, ENGLAND 
Telephone: 7 Cleeve Hill, Cheltenham. Telegrams: “‘ Adlard, Winchcombe”’ 
