When it gets dark at teatime and I need a mac even to reach the greenhouse, I have an unfailing source of garden interest. It may be nearly two hundred years old, but The Gardeners Magazine chatters away about just the things we discuss, over the fence or in the pub; the whys and wherefores of plants and soils and weather.
I just opened the 1842 volume to see what was on the agenda at the end of that year. The answer is chemistry. Great minds were pondering the importance of basic elements in the soil and the atmosphere on the growth of plants. It was all pragmatic stuff – what a Californian actress would no doubt call ‘lived experience.’ Why did plants in pots sulk in sifted soil but perk up if you added stones or grit or turf? Ditto with the effects of mulching plants in the ground. ‘The Conductor’ (who of course was the encyclopedist John Claudius Loudon) managed to have correspondents all over Europe, and even as far away as Australia. And correspondence in those days meant quill pen and inkwell. It was in 1841 that Rowland Hill introduced the penny post, the one price universal stamp that got everyone – or at least far more people – writing. Loudon reflects on the likely effect of this simple system on gardening. Suddenly sending seeds to friends became cheap and easy. Plants can travel from Cornwall to Scotland for a penny.
The 1840s were indeed a time of great changes. But what decade doesn’t see itself in retrospect as a turning point of some kind? Loudon mentions Sir Humphrey Davy, who had recently discovered oxygen, and the French chemist Chaptal as the master-chemists of the previous age. Now it was Liebig’s turn. Liebig’s great discovery was that the carbon which forms the structure of plants comes simply from the C02 in the atmosphere, not from any ground-based source. Justus von Liebig also not only discovered or invented fertilizer, but beef extract, how to preserve (ie corned) beef and even how to manufacture mirrors. You could call him Germany’s Pasteur.