Some time ago we called attention to a preliminary paper by Crawford1 on barium as a cause of "loco" in animals. Crawford's complete work has recently appeared as a bulletin of the Bureau of Plant Industry, United States Department of Agriculture.2 Although the subject of "loco" is largely of economic interest, since it causes very extensive losses of live stock in the entire western half of the United States, there is in this work much of interest to physicians.
Briefly stated, Crawford finds that certain plants, of themselves harmless, or even available as forage, frequently, when growing on certain soils, take up barium in quantities sufficient to cause poisoning, either acute or chronic, in live stock. All previous efforts to discover a poisonous principle in the so-called loco plants had failed; some believed that the condition known as "loco" was due to malnutrition or helminthiasis, while the few