ALLYL SULPHIDE — ^AMYLODEXTRINE 33 1 



and rinsing in water for a day to wash out the acid. Mount 

 sections thus treated under a coverglass with untreated sections 

 and apply reagents for detecting alkaloids. The following 

 reagents give with alkaloids amorphous or crystalline precipitates: 

 potassium iodide-iodine, potassium bismuthiodide, chloroiodide 

 of zinc, potassium-mercuriciodide, chloride of gold, ammonium- 

 molybdate, potassium permanganate. See under Aconitine, 

 Atropine, Berberin, Brucine. Caffeine, Corydalin, Curarin, 

 Cytisin, Morphine, Narceine, Narcotine, Nicotine, Piperine, 

 Sinapine, Strychnine, Theobromine, Veratrine. 



AUyl Sulphide or Garlic Oil, (CgHJ^S.— This may be 

 demonstrated by treating sections of species of Allium with 

 palladous nitrate which produces a kermes-brown precipitate; 

 or sections may be treated with a solution of silver nitrate, when 

 sulphide of silver will be formed. 



Amygdalin, C20H27NO11. — This nitrogenous glucoside is 

 particularly abundant in bitter almonds and in the bark, leaves, 

 and flowers of Prunus padus. It can be extracted in boiling 

 water, and on addition of alcohol it crystallizes out in the form 

 of pearly scales. It is split into prussic acid, oil of bitter almonds 

 and sugar by the enzyme emulsin which occurs associated with 

 the glucoside. 



Amylodextrine. — This carbohydrate occurs in those starch 

 grains which take on a reddish color with iodine, and it is formed 

 by the action of diastase and acids from the amylose of those 

 starch grains which are colored blue with iodine. By the action 

 of diastase on the starch of germinating seeds the amylose of the 

 starch is converted first into amylodextrine, and this in turn into 

 dextrine and isomaltose. The microchemical behavior of amylo- 

 dextrine is given by Arthur Meyer as follows: Water at 70° C. 

 dissolves crystals of amylodextrine slowly, while at 100° 

 the crystals are dissolved at once. A solution of 10 gm. of pure 

 calcium nitrate in 14 gm. of water dissolves crystals under the 

 coverglass very slowly. After some hours, if a solution of iodine 

 is added, the calcium nitrate solution is colored brown, which 

 indicates that the crystals of amylodextrine have at least been 



