742 FREDERICK S. HAMMETT 



anterior lobe preparations produces certain changes in gonad activity. 

 Concise allocation of gonadal disturbances in connection with pituitary 

 disorders t6 the anterior lobe was first made by Cushing(a) (1909) when he 

 attributed the clinical ^condition of dystrophia adiposogenitalis to hypo- 

 functioning of the part of the hypophysis. Increased sexual activity as a 

 result of anterior lobe administration was shown by Aschner(fr) (1912), 

 and Goetsch and Gushing (1913). This was not obtained when posterior 

 lobe extracts were used. In a later series of experiments Goetsch (a) 

 (1916) was able to demonstrate a sexual precocity in his animals. Studies 

 on egg production and hatchability by Clark (1915) seemed to show that 

 these phenomena were heightened by the addition of anterior lobe to the 

 diet of the domestic fowl, though Pearl and Surface (1915) and Pearl 

 (1916) failed to obtain such an effect, Frank (1919) also failed to obtain 

 evidence demonstrating a consistent effect on the genitalia of the adminis- 

 tration of anterior lobe extracts. Notwithstanding these latter negative 

 results clinical and other evidence sufficiently supports the belief that the 

 anterior lobe may in some way be concerned in gonadal activity. 



Isolation and Properties. "Active Principle" of Anterior Lobe. 

 We now turn to the active principle that presumably is the main factor 

 concerned in the production of the changes that have been described. To 

 Robertson (1916) is due the credit for the isolation of this com pound. 

 The method of preparation as evolved by him is rather simple. The 

 anterior lobes are ground up in a mortar with three times their weight of 

 a mixture of equal parts by weight of anhydrous sodium and calcium 

 sulphates and the whole is dried on a water bath for about an hour. This 

 mixture is pulverized and extracted with absolute alcohol at the boiling 

 temperature for forty-eight hours. The extract, after filtration, is evapo- 

 rated to a small volume under reduced pressure, cooled and mixed in a 

 cylinder with one and one-half times its volume of dry ether. After 

 standing for several hours a flocculent precipitate settles out. The super- 

 natant liquid is siphoned off and the residue is mixed with a large volume 

 of a mixture of one part by volume of absolute alcohol, and one and one- 

 half parts of dry ether. The precipitate is rapidly filtered off by suction 

 and dried at 30-35 C. for twenty-four to forty-eight hours. The resultant 

 product is a dry, cream-colored powder, which is kept in thoroughly dry 

 glass containers on account of its hygroscopic properties. The substance 

 is apparently a chemical unit from the fact that its nitrogen and phos- 

 phorus content are constant and has been named tethelin, from the Greek 

 root Tt^Xcos, growing. When the compound prepared in this manner 

 13 exposed to the air it becomes dark in color. When heated it begins to 

 darken at a temperature lying between 100 and 110 C. " Tethelin is 

 soluble in water to the extent of about five per cent, forming at that con- 

 centration a brown, turbid solution. More dilute solutions are paler in 

 color, and one per cent solutions are but slightly opalescent. The com- 



