782 EXPERIMENT STATION RECORD. [Vol.43 



alkaline reaction, while that in the'other side appeared gelatinous and gave an 

 acid reaction. Tested separately, both portions of the serum reacted negatively 

 to agglutination tests, but when brought together again exhibited the original 

 agglutinating power. The author is of the opinion that the action of the elec- 

 tric current causes the division of the agglutinins into two parts, each of which 

 has no agglutinating power. 



Effects of enzynis in serum on carbohydrates and their relation to bac- 

 teriological technique, C. Tenhkoeck {Jour. Expt. Med., 32 {1920), No. 3, pp. 

 il'iS-SJ/O). — "It has been shown that enzyms in serum will change maltose, 

 dextrin, and starch so that they will react as dextrose in media. These enzyms 

 are destroyed by heating to 60° C. [140° F.] for 15 minutes, but they are present 

 in sera that have been refrigerated for as long as IS months. The practice of 

 using carbohydrate media contaiijing unheated serum should be discouraged, 

 and if it is used the possibility that the carbohydrate may be changed by the 

 enzyms present must be considered." 



A nephelometric method of estimating the number of organisms in a 

 vaccine, G. C. Dunham {Jour. Tminunol., 5 {1920), No. Jf, pp. 337-3J,3, fig. 1).— 

 A method of estimating the numlier of organisms in a vaccine is described in 

 which the turbidity of the suspension is measured by means of a Kober nephe- 

 lometer, the standard consisting of suspensions of killed bacteria in normal salt 

 solution. The method is considered to be as accurate as the microscopical 

 count and to require less time and labor. , 



Chemical and pharmacological examination of the woody aster, O. A. 

 Beath {Wyoming Sta. Bui. 123 {1920), pp. 39-66, figs. 9).— Following a de- 

 scription of the symptoms of poisoning in sheep caused by the woody aster 

 {XylorrMza parryi), and a review of the literature on the poisonous nature of 

 the aster, a detailed report is given of an investigation of the chemical nature 

 and pharmacological effects of the poison. 



Fresh material was collected at three distinct periods of growth, when im- 

 mature, flowering, and seeding. The immature plants yielded a definite toxic 

 crystalline substance when subjected to the following treatment : The powdered, 

 air-dried material was extracted with lukewarm water, the extract filtered, con- 

 centrated to the consistency of thin sirup, and treated with a slight excess of 

 basic lead acetate. The resulting precipitate was filtered, suspended in water, 

 and treated with hydrogen sulphid to remove the lead. The process was re- 

 peated with the resulting solution xmtil the final precipitate was nearly white. 

 The aqueous concentrate from the lead treatment was digested with an excess 

 of hot 70 per cent alcohol, cooled and filtered, and the concentrated filtrate re- 

 treated with 80 per cent alcohol. After cooling in the ice box an excess of 

 ether was added and the mixture allowed to stand from 24 to 36 hours. The 

 clear liquid was removed from the sediment by decantation, concentrated, and 

 retreated with anhydrous ether. The sediment formed was added to the first 

 fraction and the mixture treated with enough water to form a paste. This was 

 mixed thoroughly with 90 per cent alcohol, filtered, and the filtrate evaporated 

 over- sulphuric acid and lime. The crystalline deposit which was obtained 

 proved to be the toxic material of the immature aster. It was also isolated in 

 the crude. state from the immature plant by extraction with 90 per cent alcohol 

 and precipitation with either water or absolute alcohol. The total yield of the 

 purified product by any of these methods averaged approximately 1 per cent of 

 the dried plant material. 



Similar ti'eatment of the seeding plants resulted in the isolation of a toxic 

 crystalline product which proved to be readily soluble in ether, although It could 

 not be extracted from the original plant with ether. The active principle was 

 present in the seeding plant in very small quantities. 



