File:PSM V74 D233 Thorium radioactive incandescent gas mantle placed above plant seeds.png

Size of this preview: 800 × 540 pixels. Other resolutions: 320 × 216 pixels | 640 × 432 pixels | 1,024 × 692 pixels | 1,280 × 865 pixels | 1,831 × 1,237 pixels.

Original file (1,831 × 1,237 pixels, file size: 628 KB, MIME type: image/png)

This is a file from the Wikimedia Commons. Information from its description page there is shown below.
Commons is a freely licensed media file repository. You can help.

Summary

Description	English: Thorium radioactive incandescent gas mantle placed above plant seeds
Date	1909
Source	Popular Science Monthly Volume 74 (January to June 1909), Page 229, Fig. 8.
Author	Unknown authorUnknown author

Experiment on the effect of radiation (from unburned thorium gas mantle) on the germination and growth of timothy grass seed.

Licensing

Public domain	This media file is in the public domain in the United States. This applies to U.S. works where the copyright has expired, often because its first publication occurred prior to January 1, 1929, and if not then due to lack of notice or renewal. See this page for further explanation.	United States
	This image might not be in the public domain outside of the United States; this especially applies in the countries and areas that do not apply the rule of the shorter term for US works, such as Canada, Mainland China (not Hong Kong or Macao), Germany, Mexico, and Switzerland. The creator and year of publication are essential information and must be provided. See Wikipedia:Public domain and Wikipedia:Copyrights for more details.