580 EXPERIMENT STATION RECORD. 



The intradermal test for tuberculosis, F. W. Poeter (Amer. Vet. Rev., J^l 

 (1912), No. .'/, pp. Ji63--i65). — After pointing out the difficulties encountered 

 with the thermal method of testing, the author reports his results of a com- 

 parative study between the thermal and intradermal tests. " Of the 60 head 

 tested by the intradermal method, all of which had reacted to the thermal test, 

 27 did not react to the intradermal test. Of this 27, 6 were considered as not 

 clearly marked either way."" 



Antituberculosis serum, A. Calmette (Bui. Inst. Pasteur, 10 (1912), No. 5, 

 pp. 193-20Jt). — This is a general review of the work done in regard to antisera 

 for tuberculosis. It deals with the following sera : Maragliano, Marmorek, 

 S. Arloing and L. Guinard, Lannelongue, Archard and Gaillard, Vallee, Jonsset, 

 Ruppel and Itichman, Bruschettini, and Rappin. The mode of action of the 

 sera is discussed critically. 



The relation of barium to the loco-weed disease (U. S. Dept. Agr., Bur. 

 Plant Indus. Bui. 246, pp. 67, figs. 15). — In a previous publication of the De- 

 partment (E. S. R., 20, p. 280) barium was held responsible for the symptoms of 

 loco poisoning. This has led to subsequent investigations, which are sum- 

 marized below : 



A field study on the relation of harimn to the loco-weed disease, C. D. Marsh 

 (pp. 7-37, figs. 15). — In order to confirm the previous conclusions, the author 

 has carried on feeding experiments with horses and cattle to determine the 

 possibility of preventing the disease, and he states that if barium is the cause 

 of loco poisoning, sulphates would form a logical antidote. Experimental ad- 

 ministration of magnesium sulphate and sulphuric acid fed in amounts much 

 greater than necessary to neutralize the barium had no antidotal effect. Ex- 

 perimental feeding of barium salts produced symptoms which corresponded in 

 general to those recorded in literature in acute poisoning, but without marked 

 cumulative effect or acquired tolerance. The post-mortem appearances corre- 

 sponded to those recorded in acute poisoning. The symptoms and pathology of 

 barium poisoning were found to differ in a marked degree from those noted in 

 loco poisoning. The author believes that typical loco poisoning is not produced 

 by barium feeding alone. 



Lal)oratory studies on the relation of barium to the loco-weed disease, C. L. 

 Alsberg and O. F. Black (pp. 39-61). — The authors have carried on laboratory 

 studies of a large number of plants to determine the action of barium in loco- 

 weed disease, particularly as connected with the possibility that plants may 

 under certain conditions derive harmful constituents from the soil. 



They conclude from their experiments with laboratory animals that the etio- 

 logical factor in loco weeds which is responsible for the toxicity of these plants 

 in laboratory experiments is not barium. This conclusion is based on the fact 

 that many plants from the Western States contain barium, but there is no evi- 

 dence that such plants injure stock upon the range. Plants in certain sections 

 of Virginia were found to contain barium in quantities that are of the same 

 order of magnitude as in loco plants, but there was no evidence that such plants 

 injure stock. In dried loco plants barium is contained in an almost insoluble 

 form. Extracts prepared by digesting with artificial gastric and pancreatic 

 juices contained but slight traces of barium, but, nevertheless, it is claimed that 

 large doses of these may be toxic. There were usually found enough salts of 

 calcium, potassium, and metals other than barium in the extract of 250 gm. of 

 dried loco plant to account for the death of rabbits. Similar extracts of alfalfa 

 may also cause death of I'abbits in similar doses. Acetic-acid extracts of the 

 ash of such barium-yielding phints from the Western States as were examined 

 contained but minute traces of barium. 



Investig'ations of the etiology of infectious abortion of cows and mares, 

 B. S. Good (Kentucky l^ita. Bui. 165, pp. 221-229, pis. 13). — The first part of 



