Page:An introduction to physiological and systematical botany (1st edition).djvu/21

 Rh are made in remote countries, and our resources of various kinds are augmented. The skill of Linnæus by the most simple observation, founded however on scientific principles, taught his countrymen to destroy an insect, the Cantharis navalis, which had cost the Swedish government many thousand pounds a year by its ravages on the timber of one dockyard only. After its metamorphoses, and the season when the fly laid its eggs, were known, all its ravages were stopped by immersing the timber in water during that period. The same great observer, by his botanical knowledge, detected the cause of a dreadful disease among the horned cattle of the north of Lapland, which had previously been thought equally unaccountable and irremediable, and of which he has given an exquisite account in his Lapland tour, as well as under Cicuta virosa, ''Engl. Bot. t. 479, in his Flora Lapponica''. One man