ritter: astragalus mollissimus. 203 



occasionally for several months show no indications of the pres- 

 ence of resin. 



Oxidases. Gum guiac solution will not turn blue except when 

 oxidases are present. It does not turn blue with any part of loco 

 weed, meaning there are no oxidases present. When hydrogen 

 peroxide is added a dark-red color appears, instead of the deeper 

 blue, which is usual for peroxidases. This may mean a peroxidase 

 is present together with some modifying substance. 



Glucosides. Sections of loco weed treated in the following 

 ways were boiled with Fehling's solution a few minutes, then 

 observations taken: 



(1) Fresh sections, no crystals. 



(2) Treated with potassium hydroxide overnight at room tempera- 



ture, cuprous oxide crystals present. 



(3) Treated with hydrochloric acid overnight at room temperature, 



cuprous oxide crystals present. 



(4) Treated with sulphuric acid overnight at room temperature, 



cuprous oxide crystals present. 



(5) Treated with alcohol overnight at room temperature, cuprous 



oxide crystals present. 



Untreated sections show crystals on long boiling with Fehling 's 

 solution. The same results were obtained when the treated sec- 

 tions were sealed with Fehling 's solution and left in a warm place 

 a few days. Sections of material preserved in formalin and treated 

 in the same way give the same results. 



These experiments may mean that glucosides are present which 

 are broken by the various reagents used, giving the test by means 

 of the freed sugar. 



Crawford says that when sulphuric acid is added to an aqueous 

 solution of harmful loco weed, it is rendered harmless because the 

 barium is taken out of solution and made into barium sulphate. 

 A section of loco weed was sealed with Fehling 's solution and kept 

 in a warm place. One week later crystals of cuprous oxide were 

 noticed, showing that no glucose was present at first, or the crys- 

 tals would have appeared sooner. It was probably a glucoside 

 broken up by long standing and heating in Fehling's solution. 

 Sections were soaked overnight in dilute sulphuric acid at room 

 temperature. The next morning they were sealed with Fehling's 

 solution. After five hours they contained many crystals of cuprous 

 oxide. What happened in a week with Fehling's solution took 

 place in a small fraction of that time with sulphuric acid. I think 

 the change in toxicity in the solution which Crawford used was 



