On Telefcopis ','^the NQuriJhmeni of Plants, (jfc, 209 



j?uBli<Tied a letter of Gerbert to the monk Conftantin, on the confl:ni(Sion of the fphere, 

 in which he fays, " fo that there will be feven perforations, in each of which you will place 

 tubes (fiftulas) of fix inches. The two extremes, or moft remote, are to be placed o;ipofite 

 each other in fuch a manner that both may be feen through as if compofing one tube. — 

 Thtfc tubes differ from mufical pipes (fiftulis organicis) in the equality of their diameter 

 throughout, for fear left any obftacle fhouid impede the fight while occupied in obferving the 

 celeftial bodies." If thefe tubes differed from thofe of mufical inftruments only in the uni- 

 formity of their bore, it is clear that they had not glafiTes ; confequentiy they were not telef- 

 copes, but dioptrx, and the glory of the invention of telefcopes mufl continue to belong to 

 the feventeenth century. 



I do not confider the celebrated opinion of Vanhelmont and Boyle as equally new, who, 

 from well-made experiments, thought that trees and plants derive their principal nourifliment 

 from water. Thefe great obfervers have informed us, that if a determinate quantity of earth 

 be weighed, and if a twig be planted in the vefFel containing this earth, it will be found 

 fcveral years afterwards upon tranfplanting the tree, that the fame quantity of earth will re- 

 main as at firft. Several centuries before Boyle and Vanhelmont, the author of the Clemen- 

 tine Recognitions had the fame idea. His words, book viii. chap, xxvii.are: "In order to 

 prove by experiment that feeds draw nothing from the earth, but are entirely fupported by 

 water, let us fuppofe that the weight of one hundred talents of earth to be put into a very large 

 receptacle, and that the feeds of various fpecies of plants be fowed therein, and abundantly 

 watered, for feveral years ; let us, moreover, fuppofe that all the feeds of wheat, barley, 

 and other vegetables, thus annually produced, to be colle£led until the quantity of grains of 

 each fhall weigh one hundred talents ; if at this period the roots be drawn out, there will ftill 

 be found in the vefTel from whence fo great a product has been obtained, the original weight of 

 one hundred talents of earth. Whence can we fay that this quantity of feeds and trees- was 

 formed i" Is it not evident that it has been produced from the vntcri" This paflage contains 

 cxaftly the fyftem of Boyle and Vanhelmont. 1 do not, however, think they have borrowed 

 it. Accurate obfervers of nature are led by their obfervations to very fimilar conclufions. 



So true it is, as Terence affirms, that. 



Nullum jam di£lum eft quod non di<Sum fit prius". 

 r may add to this chapter of Mr. Wefl"eling, which has been inferted in the Journal des 

 Savans, for February, 1679, ^^^ different proofs of the exiftence of telefcopes in the thirteenth 

 centiiry. It would follow alfo, from a pafTage of John, abbot of Beaugency, that fpecSacles: 

 were ufed for reading in the twelfth century, if the word buftula, ufed by this abbot, may 

 be tranflated fpeftacles. The following is the paflTage : " Statim ut litterarum veftrarum ba- 

 " julam vidi, buftulam arripiens, non folum avide legi et pcrlegi *." The Journal Encyclo- 



pedique, 



• This paffage has very often been quoted in favour of the invention of fpcftscles in the thirteenth cen- 

 tury. It is thought, neverthelefs, vvith much probability, that the word buttula comes from the word 



buxu> ' 



