.JOHN WILLIAM DKAl'KU. 



a Fellow of the Geological Society, three papers on scientific sub- 

 jects, yet his first independent contribution to science was from this 

 Christian sville laboratory. It appeared in the American Journal 

 of Science and Arts for July, 1834, in the form of a letter to the 

 editors, the memoir in extenso appearing in the September number 

 of the Franklin Institute Journal for the same year under the title 

 " Some experimental researches undertaken to determine the nature 

 of capillary action." During this period he devoted his attention 

 also to improvements in the construction of galvanic batteries, to 

 investigations on the alleged magnetic action of light, and to the 

 analysis of a native chloride of carbon and of certain ancient coins 

 and medals. 



Having decided to take the degree of Doctor of Medicine in course 

 Draper spent the winters of 1835 and 1836 in Philadelphia attend- 

 ing the medical lectures given in the University of Pennsylvania. 

 Here he came directly under the congenial and stimulating influence 

 of Dr. Robert I Tare's instruction in chemistry and physics, and in him 

 and in Dr. J. K. Mitchell, at that time the professor of chemistry 

 in the Jefferson Medical College, he found warm personal friends. 

 In their laboratories he did a large amount of scientific work, and 

 this not only alone, but also conjointly with these eminent men. 

 lie assisted Dr. Mitchell when he used for the first time in this 

 country the apparatus of Thilorier for the liquefaction of carbonic- 

 acid gas. 



Draper graduated from the University in March, 1836. The sub- 

 ject of his thesis, as given in the Alumni Catalogue, was " Glandular 

 Action.'' It discussed the passage of gases through various barriers 

 not having visible pores, such as soap bubbles. He showed that 

 these transfusions take place as instantaneously as if there was no 

 obstacle in the way and are attended by many curious phenomena. 

 He put one gas inside the bubble and another on the outside ; he 

 then analyzed both and showed that the movement continues until 

 the gaseous constitution is the same within and without the bubble. 

 The special application of these experiments was to ascertain what 

 goes on in the air cells of the lungs ; how oxygen is introduced into 

 the blood and carbonic acid escapes from it in the act of inspi ra- 

 tion. Current report has it that the scientific character of this 

 thesis secured for it the special commendation of the medical faculty 

 and the high honor of publication at their hands. But as the thesis 

 itself is missing from the collection of the class of 1836, preserved 



