1919] RURAL ENGINEERING. 187 



Particular reference is made to the studies of Hadley previously noted | K. S. 

 It., 37, p. 183). A list of 53 references to the literature is included. 



Some studies on the resistance of the ova of Toxascaris limbata, M. Wigdob 

 (New Orleans Med. and Swrg. Jour., 71 (11)18), No. 6, pp. 264-281).—'- Parasitic 

 ova are very resistant to various chemical disinfectants. The usually advo- 

 cated germicidal strengths are markedly effective against the ova of T. limbata 

 for many substances. The ova of T. limbata show Surprising resistance toward 

 acids, alkalis (especially against caustic soda and lime), and metallic salts. 

 Ethyl alcohol in strengths up to 70 per cent and formaldehyde in varying 

 Strengths up to approximately 40 per cent are remarkable in their ovocidal action 

 against the ova of T. limbata. 



" The phenol derivatives, primarily the cresois which have been dissociated by 

 means of snap solutions, such as preparations of [Kreso, Kreso Dip, Septico, 

 Cresylone, and Neko] (varying in their lethal action on parasitic ova according 

 to their corrosiveness), offer the best possibilities as ovocides against parasitic 

 ova of all substances tested. Most of the volatile disinfectants are apparently 

 efficacious In killing the ova of T. limbata. 



" The ova of T. limbata are evidently very resistant to conditions of drought 

 and to low temperatures and require an ample supply of oxygen for the best 

 development. Rapid development is possible at temperature as high as 37.8° C. 

 [100° F.], but the ova are killed at temperatures of 49 to 60° C, and develop- 

 ment is materially retarded at temperatures as low as 10°." 



Anthelmintics: Their efficiency as tested on earthworms, T. Soixmann 

 (Jour. Pharmacol, and Expt. Ther., 12 (1918), No. S, pp. 129-170).— The author 

 finds that all clinical anthelmintics are markedly toxic to earthworms. This 

 test may therefore be used to determine whether a given substance has any 

 anthelmintic properties, and also to determine the relative activity of different 

 samples of a given drug. The results of tests of the effect of many anthelmintics 

 are reported. 



RURAL ENGINEERING. 



Measurement of water to farms, methods, limitations of accuracy, its 

 importance to the water user, and project interests, J. S. Longwell (Reclam. 

 Rec. [V. &*.], 9 (1918), No. 10, pp. 480-484).— This article is of interest to both 

 the engineer and water user. 



Use of water on projects of the United States Reclamation Service, E. A. 

 Moiutz (Reclam. Rec. [U. 8.1, 9 (1918), No. 9, pp. 42S-430, fig. 1).— This article 

 presents some general tabular data on the experience of the U. S. Reclamation 

 Service in the use of water on its several irrigation projects. 



Tables showing quantities of water used on projects of the United States 

 Reclamation Service, its monthly distribution, and other data for the years 

 1912 to 1917, inclusive, B. A. Moiutz (Reclam. Rec. [U. 8.1, 9 (1918), No. 11, 

 pp. 532-5S8). — Detailed tables are given. 



Use of water on the Salmon River tract, E. B. Dari.ixctcx (Reclam. Rec. 

 [U. 8.1, 9 (191S), No. 5, pp. 825-228, figs. 5).— Data of general interest to irri- 

 gation engineers and water users are given. 



On ground-water movements according to isothermal curve systems, P. 

 Forciiiieimf.r (Abs. in Sci. Abs., Sect. A-Phps.. 21 (1918), No. 2-',6. pp. 252, 

 253). — This paper, dealing with subterranean water movements, is entirely 

 mathematical. 



On the variation of underground water level near a tidal river. E. G. BrL- 

 ham (Quart. Jour. Roy. Met. Soc. [London], ^ (1918), No. 187, pp. 171-189, 



