Despite the allusion just mentioned to “the experience of to-day,” our author perhaps shows too great a tendency to cite authorities to be that Adelard of Bath who wished to give and take reason and reproved his nephew for blind trust in authority. In discussing the theme of spirits and demons[103]--a different problem, it is true, from natural questions--he thinks that “it is enough in these matters to have faith in the authority of those who, divinely illuminated, could penetrate into things divine by the purer vision of the mind.” He proceeds to cite Apuleius and Trismegistus, Hermes in _The Golden Bough_, “Apollonius” in _The Secrets of Nature_, which he wrote alone in the desert, and Aristotle who tells of a spirit of Venus who came to him in a dream and instructed him as to the sacrifice which he should perform under a certain constellation. [Sidenote: Adelard’s future influence.] But I would close this chapter on Adelard not with superstition from a treatise of dubious authenticity, but rather with reaffirmation of the importance in the long history of science of his brief work, the _Natural Questions_. Its probable effects upon Hugh of St. Victor and Roger Bacon are instances of its medieval influence to which we shall add in subsequent chapters. But most impressive is the fact that within such compact compass it considers so many problems and topics that are still of interest to modern science. For instance, its two concrete examples of the stone dropped into a hole extending through the earth’s center and of the magic water jar have been common property ever since. FOOTNOTES: [26] For the _De eodem et diverso_ I have used the text printed for the first time by H. Willner, _Des Adelard von Bath Traktat De eodem et diverso, sum ersten Male herausgegeben und historischkritisch untersucht_, Münster, 1903, in _Beiträge_, IV, i. For the _Questiones naturales_ I have used the _editio princeps_ of Louvain, 1480 (?), and what is supposed to be the original MS at Eton College, 161, (Bl. 6. 16). I have also examined BN 2389, 12th century, fols. 65r-81v, _Questiones naturales_ from cap. 12 on; fols. 81v-90v, _De eodem et diverso_ (sole extant text); and BN 6415, 14th century, where Adelard’s _Natural Questions_ are found together with William of Conches’ _Dragmaticon philosophiae_ and Bernard Silvester’s _Megacosmus et microcosmus_, of which we treat in succeeding chapters. Professor H. Gollancz has recently translated the Latin text into English for the first time in his _Dodi Ve-Nechdi_, the work of Berachya based upon Adelard’s and preserved in MSS at Oxford and Munich. For Adelard’s translation of the _Liber Ezich_, or astronomical tables of Al-Khowarizmi (as revised by Maslama at Cordova), I have used H. Suter, _Die astronomischen Tafeln des Muhammed ibn Musa Al-Khwarizmi_, Copenhagen, 1914.