188 EXPERIMENT STATION RECOBD, [Vol.37 



teria in water may be made in from 20 to 40 minutes and allow of the examina- 

 tion of otlier microorganisms at the same time." 



It was found that " these counts are fully more accurate than those by the 

 plate method, altliough not directly comparable with them. The centrifugal 

 method of concentrating the bacteria after ' flocking ' is the most rapid, but is 

 less efficient and accurate than filtration. The morphological character of the 

 organi.sms themselves, rather than the appearance of tlieir growth, is con- 

 sidered in judging their possible general characteristics. The.*:e total counts 

 are in no sense intended to superseile the spe<'ific cultural and other tests for 

 Jiacillus coU or other individual groups of organisms." 



Bile compared with lactose bouillon for determining the presence of 

 Bacillus coli in water, Maud M. On.ST {Jour. Bad., 1 (1916), No. 1, pp. 75-79). — 

 Exporinionts are reporte<l in which it was found that lactose bouillon used as a 

 .substitute fr)r lactose peptone ox-bile permitted the development of about twice 

 as many B. coli from 191 samples of water as the bile medium. 



"The bile was never used later than a w»'ek after collection. It was sterili7,e<l 

 upon receipt and storetl during this period at a temperature of 1° C. It was 

 enriched with 1 i>er cent lactose and 1 per cent peptone antl tubed in Dimliam 

 tube.s. The lactose bouillon was made from neutral nutrient broth prej)are<l 

 with 0.5 per cent Liebig's meat extract. 1 i)er cent peptone, and 1 per cent 

 lacto.se. . . . 



"Lactose bouillon cost less 'n money and labor. The dllliculty of obtaining 

 pure, fresh bile puts it almost out of the reach of many workers. The .stored 

 bile proved to show progressive deterioration. Lactose bouillon can be prepared 

 when desiretl and can be made more uniform. It need contain no preciiiitate 

 t.> clog tlie inner tube or to affect the activity of the organism." 



Septic tank, L. C. Hart and (J. C. .Tonks ((,'«. State Col. .-if/r. Cirr. .}/ (/.'»/7>, 

 PP- 1, flff^- •')• — This circular briefly describes and ilust rates a .^septic tank 

 made of 24-in. terra cotta pipe. A tile absorption area for final disi)osal is 

 recommendeil. 



Breport of the joint committee on Federal aid in the construction of post 

 roads (U. S. Houxe Repre»cntatir€», 6S. Con{i., S. Se^s., Doc. 1510 (1915), pp. 

 Sn, pis. S). — This is the first reix»rt of the joint committee on Federal aid in 

 the construction of post roads. It contains the following chapters: 



Importance of good roads and Fe<leral aid; desirability of congressional con- 

 trol; review of committee's work; data from foreign countries; data from the 

 several States; tonnage transjKirtetl over rural roads; rural free delivery roads; 

 special transportation rates on material for road improvement ; comparative 

 stati.stics bearing upon Federal aid apportionment; statistics of wealtli. debt, 

 highway expenditures, etc. ; comparative statistics on cost of road construction ; 

 the old Cun)l)erland Road; instruction in highway and bridge engint»ering; 

 synopsis of good-roads bills introtluced in the Sixty-third Congress; and rword 

 on congressional action. 



Two final chapters give a table showing comparative statistics on road sys- 

 tems of foreign countries and a bibliography. A financial statement is ap- 

 pended. 



Highway trafllc analysis and trafllc census procedure, W. H. Conneix 

 (West. Enffin., 8 (1917), A'o. S. pp. 96-102, figs. -}>.— This article outlines the 

 procedure in the collection, classification, analysis, and application of traflic 

 census data in their relations to the planning of a highway, the design and 

 maintenance of pavements, the cleaning of highways, and traflic reg\dations. 



A standard of carbureter performance. O. C. Berky (Gas Engine. 19 (1911), 

 No. 4. pp. 196-200. figs. 5). — Tests on the proper carburetioQ of petroleum fuels, 

 conducted at Purdue University, are reported. 



