 He drew on the work of past generations, from the humanists onwards, consulting an enormous collection of materials in the form of text editions, dictionaries, and grammars, mostly uncritical and unreliable.Some work had been done in the way of comparison and determination of general laws, and the concept of a comparative Germanic grammar had been grasped by the Englishman George Hickes by the beginning of the 18th century, in his "Thesaurus".Ten Kate in the Netherlands had made valuable contributions to the history and comparison of Germanic languages.