1S92.] J-O" [Ruschenbergcr. 



acquainted with tlie region about us. Suddenly Dr. Leidy said, raisin i:; 

 his hands, ' Dear me ! there is a plant which Gray says only grows high 

 on the mountains, and here it is by the sea. ' He gathered a portion of it 

 with great care and put it in his pocket. When he got to the house he 



spoke of his find, and showed Mrs. the specimen. 'Why, Doctor,' 



she said, 'that is Empetrum.' The doctor looked carefully at it and said, 

 'Why, so it is ; I thought it was Loiseleuria,' and laughed heartily, 

 receiving the correction as though it had come from Gray himself.''* 



His deep interest in mineralogy was continuous from boyhood till the 

 close of his life. To him it was a kind of Sunday afternoon or holiday 

 recreation to visit friends who had cabinets, examine their newly acquired 

 specimens, and talk about them in connection with those in rival collec- 

 tions. Always seeking to obtain rare specimens, especially of gems, he 

 bought and sold and exchanged minerals with his friends whenever oppor- 

 tunity occurred. About the year 1870 he purchased a collection, said to 

 be the finest ever brought from Europe to this country, and a year or two 

 after sold it to a party in Boston for $2000, because he said he could not 

 afford to keep it. He continually added to and improved his cabinet, 

 which, at his death, was sold to the National Museum at Washington, 

 D. C, for $2800. 



He was not practically interested in the chemical analysis of minerals. 

 But through his life-long habit of examining, comparing and exchanging 

 specimens, as well as of buying and selling them, he acquired the skill of 

 an average lapidary in recognizing mineral forms, especially of gems, and 

 among his friends became an authority for their market value. Yet more 

 than once he mistook an artificial for a real stone, submitted to his inspec- 

 tion by a dealer to test his knowledge. 



Dr. Leidy had a broad chest and strong limbs, was about five feet ten 

 or eleven inches in height and 200 pounds in weight. Relatively to his 

 stature, slightly stooping at the shoulders, his head was rather small; and 

 it was ascertained after death that his brain weighed forty-five and a half 

 ounces — somewhat less than the average. But deficiency of brain tissue 

 was probably compensated for by the sustaining power of good blood- 

 circulating and digestive apparatus, upon the normal functions of which 

 mental activity in a degree depends. It is commonly known that a drink 

 of tea or of any stimulant temporarily augments the activity of the mental 

 machinery when it is moving slowly from fatigue or other cause. It is 

 generally supposed, however, that intellectual energy is in proportion to 

 the size of the brain, the prevailing weight of which in adult man is from 

 forty-six to fifty-three ounces, according to an English authority,! and from 

 forty-five to fifty-five ounces among our own people, and among all races 

 from two to four pounds, according to an American authority. | 



* In Meraoriam. Dr. Joseph Leidy, b. Sept. 9, 1823, d. April 30, 1891. Personal History. 

 By William Hunt, M.D. Read at the Academy of Natural Sciences, May 12, 1891. 



^Anatomy, Descriptive and Surgical. By Henry Gray, F.R.S. 



XAn Elementary Treatise on Human Anatomy. By Joseph Leidy, M.D., LL.D., etc. 

 Second edition, 1889. 



PROC. AMER. PHILOS. SOC. XXX. 138. U. PRINTED APRIL, 23, 1892. 



