File:Daltons Symbols.gif
The author died in 1844, so this work is in the public domain in its country of origin and other countries and areas where the copyright term is the author's life plus 100 years or fewer.
This file has been identified as being free of known restrictions under copyright law, including all related and neighboring rights.
This work is in the public domain in the United States because it was published (or registered with the U.S. Copyright Office) before January 1, 1929.
