Litmus solution being added to an alkali. Litmus is an indicator, a chemical that has a different colour depending on whether it is in an acidic or alkaline environment. In alkalis it is purple/blue. In acids it turns red. Litmus is derived from the lichen Lecanora tartarea. For litmus being added to an acid, see image A500/482.
04 June 2004
2.7 MB (3667 x 4968 px) 31.05 x 42.06 cm / 12.22 x 16.56 inch @ 300dpi/118.11ppc Uncompressed size 52.12MB
Rights Managed (RM) – Non Exclusive
Not Released (NR)
THE SCIENCE PHOTO LIBRARY
Science Photo Library
Why is the file size on download smaller than the file size I selected?