394 EXPEEIMENT STATION EECOKD. 



48). — Several serious outbreaks of this disease occurred and were investigated by the 

 authors. The first symptoms were fever, followed by colicky attacks. Some of the 

 horses died within 2 hours. A post-mortem examination disclosed perforating 

 ulcers of the intestines and inflammation of the coecum. One attack of the disease 

 did not confer immunity to further attacks. The period of incubation was appar- 

 ently from 8 to 14 days. From affected organs of horses the authors isolated B. coli 

 in great quantities and found that it possessed an especially high virulence. An 

 attempt to inoculate a horse by means of feeding this culture was without results. 

 Intravenous injection, however, of the organism caused the death of the experi- 

 mental animal. In case of further outbreaks of this disease the authors recommend 

 an immediate and complete change of diet. 



On the question -whether bacteria can penetrate through the ■wall of the 

 healthy alimentary tract, A. Schott {Centbl. Bakt. u. Par., 1. Abt., 29 {1900), 

 X().'<. 6, pp. 239-256; 7, pp. 291-297). — This article contains an extended discussion of 

 the literature of the subject in connection with a bibliography. The evidence thus 

 far brought together does not support the belief that i)athogenic or nonpathogenic 

 bacteria can penetrate through the wall of the normal intestines. 



AGRICULTURAL ENGINEERING. 



A text-book of the physics of agriculture, F. H. King {Madison, Wis.: Author, 

 1901, 2. ed., pp. XVI-\-604, Jigs. 276). — In this book, as Professor King states, "the 

 aim has been to present to the student who expects to be a farmer some of the fun- 

 damental principles he must understand to become successful." The author states 

 that it is his purpose to present these principles from the physical rather than the 

 chemical or biological standpoint, and from that of the general student and farmer 

 rather than from that of more technical scientific agriculture. Nevertheless the 

 book will be found to be a notable contribution to the literature of scientific agri- 

 culture in a field which has not heretofore received the attention its importance 

 demands. The introduction deals briefiy with certain general physical principles, 

 laws, and factors, a knowledge of which is necessary to an miderstanding of their 

 subsequent practical api^lication. Other chapters deal with the nature, origin, and 

 waste of soils; chemical and mineral nature of soils; soluble salts in soils; physical 

 nature of soils; soil moisture; physics of plant breathing and root action; movements 

 of soil moisture; conservation of soil moisture; relation of air to soils; soil tempera- 

 ture; objects, methods, and implements of tillage (especially the plow) ; ground 

 water, farm wells, and drainage; principles of rural architecture, including strength 

 of materials (posts, barn frames, etc.), warmth, light, and ventilation, principles of 

 construction, construction of silos; farm mechanics, including principles of draft, con- 

 strui'tion and maintenance of country roads, farm motors (animal power, steam and 

 gasoline engines, and windmills) ; farm machinery (general principles, belting, farm 

 pumps, hydraulic rams) ; principles of weather forecasting, including discussions of 

 the atmosphere and its movements, and weather changes. 



Cold-storage experiments, J. B. Reynolds {Ontario Ayr. Col. and Expt. Farm 

 apt. 1900, pp. 3-7, figs. 3). — Observations are reported on the amount of ice con- 

 sumed by absorption through the walls of a refrigerator constructed on the plan 

 recommended by the Dominion government. The refrigerator used had a door at 

 the top opening into an ice-1 )Ox and another in front opening into the cooling cham- 

 ber. Three galvanized-iron tubes extended from the ice-box to a trough at the bot- 

 tom of the cooling chamber. These served to carry off the water from the ice-box 

 and were filled with a mixture of ice and salt in place of the ice in the box when it 

 was desired to reduce the temperature of the refrigerator to a lower degree than 

 could be obtained with the ice alone. A record was kept of the temperature inside 



