86 UNCLASSIFIED PUBLICATIONS [BoT. Absts., Vol. Vll, 



MISCELLANEOUS, UNCLASSIFIED PUBLICATIONS 



Burton E. Livingston, Editor 



552. Anonymous. Microscoptical optics. [From a paper by A. E. Conradt at a dis- 

 cussion on the microscope at the Royal Society on Jan. 14.] Nature 104: 548-550. 1920. 



553. Anonymous. Peat fiber and the textile industry. Jour. Amer. Peat Soc. 13 : 350. 

 1920. 



554. Anonymous. [Rev. of : Alcock, W. Broughton. Canvas destroying fungi. Journ. 

 Roy. Army Med. Corps 32«. Dec, 1919.] Jour. Trop. Med. and Hygiene 23:41. 1920.— 

 Researches in Malta and Italy show that the rotting of canvas is due to various fungi, but 

 chiefly to species of Macrosporium and Stemphylium. — E. A. Bessey. 



555. Barnard, J. E. Construction and use of miscroscopes. Nature 104:546-548. 

 1920. — Opening paper of a discussion on the microscope at the Royal Society on Jan. 14. 

 Most microscopes are unstable. An object on the stage will not maintain its centration 

 if the instrument is put into the horizontal. Imperfections in mechanical stages are gen- 

 eral. Resolution, not magnification, is the primary function of an objective. No indica- 

 tion that numerical aperture will be further increased, but advances in illumination, espe- 

 cially by use of ultra-violet or perhaps still shorter radiations, may be hoped for. (See also 

 Bot. Absts. 3, Entry 3033.)— 0. A. Stevens. 



556. Brown, A. M. Faults found in butter. Their definitions, causes and some sug- 

 gested remedies for same. Agric. Gaz. New South Wales 31:490-494, 591-595. 1920. — 

 Author discusses relation of certain bad characters found in butter to bacteria and fungi 

 causing them. — L. R. Waldron. 



557. Deelen, H. Peat fiber spinning. Jour. Amer. Peat Soc. 13 : 452. 1920. — German 

 patent 316,511 covers the preparation from peat of fibers suitable for use with wool, cotton, 

 or jute. — G. B. Rigg. 



558. DuGGAR, B. M. Some factors in research. Plant World 22:277-289. 1919.— A 

 paper contributed to a symposium on the general topic "Our present duty as botanists," in 

 Baltimore, 1918. Various factors are discussed, such as the establishment of research posi- 

 tions in connection with industrial enterprises, extension of opportunities to use special 

 apparatus during vacation periods, conferences of groups of investigators interested in related 

 problems, fostering post-doctorate and sabbatical-leave research, co-operation in publication 

 and other activities, etc. It closes with a plea for better preparation, particularly in chemis- 

 try, for botanical research. — Charles A. Shull. 



559. Fischer, Herman. Der Nahrstoffgehalt unserer Gewasser und seine Ausniitzung 

 fiir die Urproduktion. [The nutrient content of our waters and its use as an original productive 

 factor.] Naturwiss. Zeitschr. Forst- u. Landw. 18: 66-83. 1920. — Agriculture has received 

 too little study in the past when compared with its relative economic importance. The 

 author discusses previous studies in this field, and dwells particularly on the relation of 

 nitrogen, phosphoric acid, and potassium as found in fresh and salt waters to aquatic life, 

 vegetative and piscatorial. Nitrogen and P2O5 are similar in salt and fresh water. In 

 rivers, lakes, and other small natural bodies, the quantity of nutrients, especially of P3O5 

 is greatly influenced by the character of the soil surface, quantity of precipitation, etc. 

 The humus coloring of water is a direct indication of the P2O6 content; and in general, all 

 waters of limestone formations contain little, those over sandstone plentiful P2O5. Although 

 further experimentation is necessary, it is believed that increased P2O0 content in natural 

 waters can be used in securing greater fish production; also, as the floor decreases in nitrog- 

 enous compounds, an increase in nitrogen is necessary to keep up production. The rela- 



