460 THE DUCTLESS GLANDS. 



bodies. Abel, who claims to have isolated the blood-pressure-raising 

 principle of the glands, states that this must in all probability be 

 classed with the pyrrol compounds or with the pyridin bases or alka- 

 loids. He was unable, however, to obtain the free base, which he 

 terms epinephrin, in crystalline form. Pyrocatechin could not be 

 split off from this product on boiling with an acid, but he states that 

 a carmin-red pigment can be separated from the sulphate of the 

 active principle without destroying its power to raise the blood- 

 pressure. 



v. Furth, who calls the active principle suprarenin, was likewise 

 not able to obtain it in pure form. 



Later, Takamine announced that he had succeeded in isolating 

 the blood-pressure-raising constituent of the gland in a stable and 

 crystalline form. This substance he terms adrenalin. 



Adrenalin is a light, white crystalline substance, of a slightly 

 bitter taste, leaving a numb feeling on the tongue where it has been 

 applied. When dry, it is perfectly stable. On heating, it turns 

 brown at 205 C. At 207 C. it melts, and is at the same time 

 decomposed. Its reaction is slightly alkaline. In cold water it is 

 soluble with difficulty, but more readily so in hot water. From its 

 hot solution it crystallizes out on cooling. It is easily soluble in 

 acids and alkalies, but not in ammonia or solutions of the alkaline 

 carbonates. Upon the addition of ferric chloride its solutions are 

 colored a fine emerald-green, which changes to a purple and then to 

 a carmin red upon the careful addition of caustic alkali. Strong acids 

 prevent the reaction, limiting the change of color to a dirty yellow- 

 ish-green. It reduces silver salts and auric chloride very ener- 

 getically, while the liquid at the same time turns red. This also 

 occurs on treating with oxidizing agents, such as potassium ferri- 

 cyanide and potassium bichromate. The usual alkaloidal reagents 

 do not precipitate the substance. With acids it forms salts, but 

 these have not been obtained in crystalline form. 



Abel's most recent analysis of his epinephrin hydrate only differs 

 from Takamine's adrenalin by one-half a molecule of water ; its 

 formula is C 10 H 13 NO 3 .JH 2 O. Its structural composition is still 

 unknown. 



The blood-pressure-raising power of adrenalin is very marked. 

 The amount pro kilo of body-weight which is required to raise the 

 blood-pressure 14 Hgmm. beyond the normal is one-millionth part 

 of a gramme, and distinct physiological effects can be obtained by the 

 administration of even one-fourteenth millionth part of a gramme. 



Aside from the blood-pressure-raising properties the adrenal 

 glands are also of interest from the fact that hypodermic injec- 

 tion of adrenal extract results in glucosuria, even though carbohy- 

 drates have been excluded from the diet of the animal (dogs). The 

 amount of sugar which may appear is at times considerable, viz., 

 3.8 per cent. Analogous results are obtained during starvation and 

 at a time when the liver is free from glycogen. The glucosuria 



