THE JOURNAL OF PHARMACOLOGY. 



15 



shake for a minute. Various fats show 

 differences in color, and in the ease with 

 which they solidify. 



Olive oil peanut and oil harden most 

 rapidly. 



According to other authorities, 50 ccs. 

 of the oil are mixed with 12 g. mercury 

 and 15 g. nitric acid (sp. gr. 1.35), by 

 which treatment only olive and oil of 

 almonds are solidified, all other oils re- 

 maining liquid. 



Pradine's reagent for foreign coloring 

 matters in wine is a saturated solution of 

 ammonia gas in ether. Upon shaking 

 this solution with wine, the foreign col- 

 oring matters are dissolved in the ether. 



Preyer's test for carbon monoxide in 

 the blood. 3 — 4 drops of the suspected 

 are warmed for 5 minutes at 30 C. with 

 10 ccs. water and 5 ccs. potassium cyan- 

 ide solution (1:2.) While the spectrum 

 of normal blood, when treated as above, 

 looses the absorption line of oxy-hsemo- 

 globin, and in its place shows a broad 

 absorption band, the spectrum of carbon 

 monoxide blood remains unchanged. 



Payer's hydrocyanic acid reaction. 

 The reagent employed is a very dilute 

 alcoholic tincture of guaiac resin, con- 

 taining a trace of copper sulphate solu- 

 tion. Upon approaching this mixture, 

 contained in a porcelain capsule, with a 

 glass rod moistened with hydrocyanic 

 acid, blue lines are formed in the liquid ; 

 upon stirring, the whole solution turns 

 blue. 



Compare Schonbein and Pagenstecher* 's 

 reaction. 



Prollius' solution for extracting cin- 

 chona bark (for the determination of 

 alkaloids) is a mixture of 88 p. ether, 8 

 p. absolute alcohol, and 4 p. water of 

 ammonia. 



Purdy's solution for estimating glu- 

 cose contains 4.15 g. copper sulphate, 10 

 g. mannite, 20.4 g. caustic potash, 300 

 ccs. ammonia water (sp. gr. 0.88), 50 g. 

 glycerin, and enough water to make 1 

 litre. 25 ccs. of this solution are reduced 

 by 0.015 g. grape sugar. 



Compare Peking's solution. 



Puscher's test for alcohol in ethereal 

 oils. Into the bottom of a test-tube in- 

 troduce a few drops of the ethereal oil 

 and dust the upper portion of the tube 

 with powdered fuchsin, or introduce the 

 latter by means of a swab of cotton. 

 Upon boiling, the alcohol evaporates first 

 and dissolves the fuchsin to a red solu- 

 tion. 



Rafaele's modification of Spiegler's 

 reagent (q. v.). 



Raspail's reaction for albumens. These 

 are colored red by sugar and concentrated 

 sulphuric acid. 



Compare Schultze'i furfurol reaction. 



Reich's reaction for cane sugar. So- 

 lutions of cane sugar, when treated with 

 cobalt nitrate solution, yield a violet 

 coloration upon the addition of soda lye. 

 According to Dupont, this reaction is not 

 interfered with by glycerin, milk sugar, 

 glucose or invert sugar; however, dextrin 

 and gums should be removed by precipi- 

 tation with lead acetate or baryta water. 



Reichardt's test for arsenic in the 

 urine. 200 ccs. of urine are concentrated 

 with about 2 g. of caustic soda, the resi- 

 due dissolved in a little water, acidulated 

 with hydrochloric acid, and then tested 

 in a Marsh's apparatus. 



Reichardt's reaction for nitric acid 

 (brucine reaction). Upon treating a so- 

 lution of brucine in concentrated sul- 

 phuric acid, with a few drops of a solution 



