To Dr. John Hall Gladstone, F.R.S., (1827-1902, English chemist), saying that he has just got back from a trip that took me away from Giessen for several weeks, thanking him for his letter of April 18 and your paper about the behaviou of sulphur when added to PCl 5. This will be recorded in one of the next issues of the Annals. The news that you have been able to confirm the chlorine, phosphorus and nitrogen compound, thus obtaining a new tri-basic acid, was of enormous interest to me...As my health is now so much better, the course of lectures I am giving this summer no longer causes me any anxiety. Please give my respects to Prof. Graham [Thomas Graham, 1805-1869, Professor of Chemistry at University College, London, 1837-1855], he is certainly in the best position for giving you the means to determine small amounts of light carburetted hydrogen...." These last three words are written in English. Signed, "Dr. Just Liebig."
Liebig at Giessen pioneered the use of chemical laboratories for students, as opposed to mere lectures, and his pupils came from all over Europe. He made fundamental advances in inorganic and organic chemistry, particularly descriptions in terms of radicals. He then turned to applied human and animal chemistry, then agriculture, which he considered the foundation of all trade and industry, and to fertilizers. He is also famous for his food for children and for Liebig’s ‘extract of meat’. Graham is famous for his law on the rate of diffusion of gases. Gladstone became Professor at the Royal Institution in 1874.