VIII. DR. DAVID ALTER, A NEARLY FORGOTTEN PENN- 



SYLVANIAN, WHO WAS THE FIRST DISCOVERER 



OF SPECTRUM ANALYSIS. 1 



By W. J. Hoi. i. and. 



A few years ago Dr. Frank Cowan of Greensburg, Pennsylvania, 

 died, and through the kindness of a friend, who had known him for 

 many years, the Carnegie Museum came into possession of his sci- 

 entific collections. Among his treasures was a prism, which I have 

 the pleasure of exhibiting. It was made out of a piece of glass which 

 composed a part of a large mass found in the ruins of Bakewell's 

 glasshouse after the disastrous fire, which on April ioth, 1845, nearly 

 destroyed the city of Pittsburgh. It was made by Dr. David Alter, 

 of Freeport, Pennsylvania, a physician of inquiring and ingenious 

 mind, who was early in life attracted to the study of electricity and 

 chemistry, having as a boy read the story of Franklin, and who, quite 

 independently, and yet in fact before the discovery of Morse, invented 

 a crude system of telegraphing. 



There was no connection between himself and Morse, and Dr. Alter 

 was most emphatic in disclaiming any credit for the introduction of 

 the telegraphic apparatus which the genius of Morse evolved. 



In the year 1853, Dr. Alter having made the prism, which I hold in 

 my hand, began a series of experiments an account of which was 

 published in November, 1854, in Silliman's American Journal of 

 Science and Art, Second Series, Volume XVIII, p. 55. The title of 

 the article is as follows: 



"Article VI. — On certain Physical Properties of Light produced 

 by the combustion of different metals in the Electric Spark, re- 

 fracted by a prism; by David Alter, M.D., Freeport, Penn." 



He began his article by saying: "We are indebted to the celebrated 

 Mr. Frauenhofer for the fact that the solar spectrum is covered by 

 numerous fixed lines, and that the light of some of the fixed stars 

 differs from that of the sun in the number and situation of the?e lines. 



1 Read before the Academy of Natural Sciences of Philadelphia on the morning 

 of the Centenary meeting, March 20, 1912. 



215 



