39 8 THE POPULAR SCIENCE MONTHLY. 



freely from the materials before us so as to present to our readers as 

 faithfully as possible the considerations on the strength of which the 

 claims of Mayer first became recognized. 



As regards the life of Mayer the details are meager. He was born 

 in Heilbronn, Wiirtemberg, November 25, 1814. He received his early 

 education in the gymnasium of his native town, and studied medicine 

 at Tubingen, finishing his course in Munich and Paris. In 1840 he 

 made a voyage on a Dutch freighter to Java, and spent the summer of 

 that year in professional practice at Batavia. Returning to Heil- 

 bronn he first became county wound-physician, and afterward phy- 

 sician to the city, and while giving the main portion of his time to 

 professional labors he devoted himself systematically, and with great 

 assiduity, to original scientific researches on the wide subject of the 

 " Conservation of Forces." In the revolution of 1848 Dr. Mayer took 

 what was called the side of order, which roused against him the antag- 

 onism of many of his neighbors. He believed that he had made very 

 important discoveries which were unrecognized and were ascribed to 

 others, while his scientific works were attacked and discredited in a 

 way that preyed upon his feelings and disturbed his mind. This was 

 aggravated by the loss of his children, and he fell into an excited and 

 sleepless condition. Being suddenly seized with a fit of delirium on 

 May 28, 1850, he quitted his bed and leaped from a second-story win- 

 dow, thirty feet high, to the street below. He recovered from the 

 shock, but his mind was so seriously affected that he was sent to a 

 lunatic asylum. Dr. Mtilburger, physician to the institution, states 

 that the equilibrium of his mental and emotional nature was seri- 

 ously affected, one of the symptoms being that, "if you conversed 

 with him about a scientific topic, it was very hard to keep him to the 

 point : his ideas were profound, it is true, surprisingly so, but they 

 came disconnected ; they went to the heart of the subject, but they did 

 not hold on to it. He was subject to occasional fits of uncontrollable 

 rage, and on feeling them coming on he would ask to be put in one of 

 the strong cells of the asylum. These fits came on only three or four 

 times during the four months he spent at the asylum, and they did 

 not last long. He had a very strong thirst for spirituous liquors, an 

 inclination which was the result of his mental malady, and the grati- 

 fication of which increased it." He was at length restored to health, 

 and busied himself with grape culture at Heilbronn. He died in his 

 native town on March 20, 1878, aged sixty-three years. 



The following lucid account of Mayer's labors and judicial estimate 

 of his position were made by Professor Tyndall in 1871, and are so ad- 

 mirable that we quote them in full, in preference to anything that it 

 would be possible for us to write : 



Dr. Julius Kobert Mayer was educated for the medical profession. In the 

 summer of 1840, as he himself informs us, he was at Java, and there observed 

 that the venous blood of -some of his patients had a singularly bright red color. 



