188 E. G. HOSKINS 



fluenced'by toxic doses. None of these studies cast any significant light 

 upon the physiology of the gland. 



Oliver and Schafer used several sorts of extracts aqueous, alcoholic, 

 and glycerin. Sometimes the fresh tissue was extracted, but often it was 

 desiccated and thus preserved, the extracts being made up from the dried 

 material as needed. The suprarenal material was derived mainly from 

 calves, but some also from sheep, guinea-pigs, cats, dogs, and man. The 

 effects in general were similar with all types of preparations, with the 

 exception of the fact that dry alcohol or dry ether failed to extract any 

 active substance from perfectly dry tissue. 



The experiments were carried out mostly on dogs, but cats, rabbits, 

 guinea-pigs, and one monkey were also used. Generally, chloroform-mor- 

 phin anesthesia was employed. The extracts were ordinarily adminis- 

 tered by vein. The dosage varied somewhat but was usually less than the 

 equivalent of 0.2 gm. of fresh gland. Maximum effects were obtained 

 when doses of 1.5 mg. of fresh gland per kilogram of body weight were 

 used. 



Some observations were made upon the effect of subcutaneous ad- 

 ministration. It was found in case of dogs and cats that only relatively 

 large doses produced any effect at all. With these slight transitory dis- 

 turbances of the pulse rate, the respiration and the temperature were 

 noted. These were accompanied by more or less hebetude of a few hours' 

 duration. Rabbits, on the other hand, frequently reacted much more strik- 

 ingly. With larger doses death often resulted ; smaller doses produced no 

 evident effect. 



A large part of Oliver and Schafer' s paper is devoted to a discussion 

 of the effect of suprarenal extract upon the arterial system. In these 

 studies four methods were used: (1) Blood-pressure was determined by 

 means of the mercury manometer; (2) Plethysmographic studies were 

 made of the changes in the volume of the limbs, spleen, and kidneys; (3) 

 The arterial system of pithed frogs was perfused with saline solutions 

 to which suprarenal extracts in various concentrations were added and 

 the effects on the rate of outflow noted; (4) Finally, direct ocular observa- 

 tions of large and small blood-vessels were made. 



Very striking evidence was obtained that suprarenal extracts contain 

 some substance which has a powerful constricting effect upon the arterioles 

 of the body. This constriction led to a remarkable rise of blood-pressure, 

 even when accompanied, as was usually the case, by cardiac depression. 

 In the frog perfusion preparations so great was the arteriolar contraction 

 that the outflow was almost completely abolished. In the larger arteries 

 of the experimental mammals "passive expansion" was noted. In the 

 plethysmographic experiments the effects in the different organs varied. 

 The kidneys and spleen diminish greatly in volume, although a prelim- 

 inary expansion was not infrequently seen. In the limb, contraction was 



