f 



386 EXPERIMENT STATION EE(M)RI). 1 Vol. 43 



Tlie 1' rot luetic 111 oi" an iinlitoxic serum is tlioujilit to prove that the toxie sub- 

 stance contained in the muscle tiltrale is a genuine tuxin and not a detinite 

 chemical substance of an aniin character. 



Because of the enormous resistance of the spores of this organism to lieat and 

 to ordinary disinfectants, the usual methods for preparing the field of inocula- 

 tion are ineffective. The authors have been unable to demonstrate the presence 

 of this bacillus in hog cholera serum virus. 



Scrapings made from the skin and Ijristles from the axillary region of a lot of 

 pgs from the same district in Arkansas from which the affected pigs originated 

 were examined and inoculations made of guinea pigs. An organism was recov- 

 ered which was morphologically and culturally identical with the one obtained 

 from pigs dying from malignant edema. 



" The experimental investigations have shown that a highly potent serum can 

 be produced by immunizing animals with the toxin of the malignant edema 

 bacillus. At pre.sent we are not prepared to state the therapeutic value of such 

 an antitoxic serum in foiidroyant cases of malignant edema, but the situation 

 might be handled by using an antitoxic serum as a prophylactic in herds where 

 previous outbreaks have occurred. This antitoxic serum could be mixed witli 

 hog cholera serum and used in conjunction with the latter product. At present 

 such a serum is not obtainable commercially. However, if the losses from 

 malignant edema following simultaneous vaccination are increased to an alarm- 

 ing extent an antitoxic serum can easily be pre}iared in any quantity." 



Swamp fever in horses (North Dakota Sta. Bui. 136 {1920), p. 21).— Brief 

 reference is made to the administration of extracts of Gastrophilus in experi- 

 ments under way. The injection of blood from an experimentally induced case 

 of swamp fever into normal horses showed the horse to continue to be a car- 

 rier of the infection after 10 and 11 years, respectively. 



RURAL ENGINEERINa. 



study of relation of soil, water, and crop with respect to irrigjation and 

 dry farming supplemented by irrigation, 1916-18 (New ]\[e.rico ^ta. Rpt. 

 1919, pp. 26, 21). — Three years' study on the movement and distribution of 

 moisture in soil showed that 24 hours after irrigation the first foot of soil con- 

 tained an average of 12 per cent moisture, with a diminishing amount toward 

 the bottom. The percentage of moisture in the first foot 24 hours after irriga- 

 tion was practically the same regardless of whether the land was fallowed or 

 cropped. There was considerable irregularity in the downward movement of 

 water after irrigation, both as to its rate of movement and amoimt held at 

 various depths. Cropped plats receiving 5 in. of water at each irrigation, with 

 a total of 55 or 60 in. per season, showed that pi-actically none of the water 

 percolated beyond the reach of plant roots. Cropped plats receiving 3 in. of 

 water at each irrigation, with a total of 40 to 45 in. a season, showed that the 

 maximum depth of penetration was about 4 ft. Fallow plats receiving 3 in. of 

 water, with a total of 15 to 18 in. during tlie season, showed no percolation be- 

 yond 10 f t. ; while 5-in. fallow plats receiving a total of 25 or 30 in. during the 

 season showed considerable percolation beyond the depth of 10 ft. 



Subsoil water in relation to tube wells, T. A. Miller-Brow nlie {Indian 

 and East. Engin., n. ser., 45 {1919), No. 6, pp. 191-193; aha. in Engin. and 

 Contract., 53 {1920), No. 13, pp. 3.55, 356).— It is stated that observation of a 

 large number of tube-well installations has led to the conclusion that the 

 engineers responsible for carrying out these works have never examined the 

 conditions covering underground water supply. The object of this paper is 

 to show that under normal conditions a permanent, fixed supply from tube 



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