378 On Spontaneous Generation. 



which throughout Thuringia I have only found on the space 

 between the foundation walls of ruined castles and the ground.* 



Eighteen years ago Major Beatson wished to introduce in- 

 to England, a new system of manuring with burnt clay, as 

 exposed in his work, 'A new system of cultivation, without 

 lime or dung,' 1820, which he himself tried, on an extensive 

 scale, at Knowle Farm, in Sussex. If my views be not with- 

 out some foundation in fact, we should suppose that other 

 weeds, as those found on the neighbouring farms, must have 

 made their appearance on Knowle farm, by spontaneous ge- 

 neration. 



It is true that a great number of seeds are annually carried 

 away by the water, and floated to other localities, both above 

 and under the ground. But they are, of course, carried to 

 lower localities, where they are decomposed, because the soil 

 does not suit their nature. But for that, the collectors of bo- 

 tanical specimens need only go to the lowest locality of any 

 hydrographical district, to find there the whole of its flora ; 

 whereas for the seven years during which I was employed in 

 collecting such specimens for a school, I met with but few 

 instances of the translocation of plants, besides those which 

 were favourable to spontaneous generation, inasmuch as a no- 

 table change had been effected in the ground itself, or the 

 vegetation which covered it before. 



Those seeds, however, which are floated by water under- 

 ground, must likewise lose, in their muddy mediunm, the pow- 

 er of germinating, long before they can be deposited in places 

 where they are hermetically sealed up to keep for an indefi- 

 nite length of time. I know an instancef in which the snow 

 water, which collects in a valley enclosed by mountains of 

 granite, porphyry, sandstone and limestone, in due succession 

 on each side, forms, every spring, a temporary lake on a mea- 

 dow, which was formerly an artificial lake, but which has be- 

 come drained, and can never again be permanently submerged, 

 on account of the water having broken through the superfi- 

 cial strata, into a sort of natural tunnel, into which the snow 

 water empties itself within a day or two, carrying down with 

 the other detritus of the mountains, innumerable seeds of all 

 sorts ; the same water forms swamps about two English miles 

 lower down the valley, but as might be expected, not one of 



* I may here refer to an interesting observation made by Dr. Retzius, of 

 Lund, who, eighteen years ago, kept a solution of muriate of baiytes in dis- 

 tilled water, in a well-stoppered glass bottle, for six months ; after which 

 time a Conferva had formed in it, which Professor Agardh declared to be 

 quite new. 



f Near the ancient abbey of Remhardsbrunn, in the duchy of Gotha. 



