882 EXPERIMENT STATION RECORD. IVol. 37 



feld filter was found to restrain the immune bodies of the serum as well as the 

 Chamberland filter. " When Berkefold filtrate was in turn passed through a 

 Chamberland F filter, the resulting residuum was not sufficiently potent in a 

 dose of 20 cc. to protect the test animal" against simultane<^us inoculation with 

 2 cc. of hog-cholera virus." 



A potent bacteria-free antihog-cholera serum could not be obtained by filtra- 

 tion through either Berkefeld or Chamberland F candles. It is indicated that 

 absorption of the proteins in the blood serum always takes place in the filter 

 pores, so that finally the filtration is actually through a colloid filter. With 

 such a condition, the first portion of the filtrate passing through the candles 

 may have contained immune bodies, while the latter portion may have been 

 free of these products. 



The possibility of the production of a potent bacteria-free antihog-cholera 

 serum by filtration of serum obtained through normal clotting or by centrifu- 

 galizing defibrinated blood is noted. No experiments to determine this, how- 

 ever, were carried out. 



Hog cholera control, R. A. Craig and L. C. Kigin (Imiiana Sta. Circ. 62 

 (1917), pp. 8, figs. 9). — A popular summary of information on hog cholera and 

 measures for its control. 



The statistics for Indiana show that the death rate in hogs in that State 

 varies from 6.2 to 24.7 per cent per year. The average for a period of six years 

 (iniO-1915) was about 13 per cent. 



Sanitary measures to prevent hog cholera, R. Graham (Illinois Sta. Circ. 

 203 (1917), pp. 3-8). — A popuhir .summary of information. 



Crude oil for hogs, .7. M. Evvakd (Iowa Agr., 18 (1917), No. 5, pp. 207, 208).— 

 The author recommends the use of crude oil for the destruction of lice and 

 nits on hogs, applied by .sprinkling over them. 



EURAL ENGINEERING. 



Construction and use of farm weirs, V. M. Conk (U. S. Dcpt. Agr., Farmers' 

 Bui. 81S (1917), pp. 18, figs. 5). — This is based on work done under a cooi^er- 

 ative agreement between the Office of Experiment Stations of the U. S. IV- 

 partment of Agriculture and the Colorado Experiment Station. Its purffose is 

 to give practical directions for the construction and use of the smaller sizes 

 of weirs, such as are suited to the measurement of water on irrigated farms. 

 A technical report on the experimental data involved has been previously noted 

 (E. S. R., 34, p. 881). 



A new evaporation formula developed, R. E. Horton (Engirt. Ncirs-Rcr., 78 

 (1917), No. 4. pp. 196-199. fig. 1). — An empirical statement based on physical 

 laws is given which was found to agree with observed facts and is held to be 

 an improvement over existing fornmlas. The working formula is E=C 

 [<i, v-u] in which E=evaporation, C=a constant, V=vapor pre.ssure corre- 

 sponding to liquid surface temperature, and r=atmospheric vapor pressure. 

 A diagram is given showing values of ^, the wind factor variation for different 

 wind velocities. 



Investigations along the central and lower Volga region. — I, Irrigation in 

 the Novouzensk districl. — Basin of the Greater Utzen, N. S. Frolov (Trudy 

 Orgnnizatsn po Izyskaniilim i Raboiam v Srcdnoti i Nizhnew Povolzh'{^. vol. S, 

 pt. 1, sect. 1, Oroshcnie v Norouze7i.9ko7n UQzdtl'. Saratov: Min. Zcml., 191,5. pp. 

 IV-\-2S0, pis. 16). — This volume covers the hi.story and economics of irrigation 

 in the Novouzensk district and gives the program and extent of irrigation In- 

 vestigations, special attention being given to so-called silt irrigation. 



