The severest blow to West Indian sugar was the development of an alternative to the sugar cane that could grow in northern climates. In 1747, a Prussian chemist, Andreas Marggraf, showed that by using brandy to extract the juice of the white beet (Beta vulgaris, var. altissima), a common European vegetable, he could isolate crystals that were identical to those purified from sugar cane, and in comparable quantities. Marggraf foresaw a kind of cottage industry by which individual farmers could satisfy their own needs for sugar, but this never came about, and many years passed before the idea escaped the laboratory. In 1811, the Emperor Napoleon officially set the goal of freeing France from dependence on the English colonies for various commodities, and in 1812 personally awarded a medal to Benjamin Delessert, who had developed a working sugar-beet factory. In the next year, 300 such factories sprang up. A treaty resuming trade between France and England was signed in 1814, making West Indian sugar available once again, and the fledgling industry crashed as suddenly as it had begun. But it rose again in the 1840s and has flourished ever since.