CIV NOTES. 



C 92 ) p. 319. Dante, Divina Commedia, Purgatorio, canto iii. 

 C 98 ) p. 320. Humboldt sur les Lignes isothermes, in the " Memoires de 

 physique et de chimie de la Societe d'Arcueil," T. iii. Paris, 1817, p. 143 

 165 ; Knight, in Transactions of the Horticultural Society of London, Vol. i. 

 p. 32 ; Watson, Remarks on the Geographical Distribution of British Plants, 

 1835, p. 60 ; Trevelyan, in Jameson's Edinburgh New Phil. Journal, No. 18, 

 p. 154; Mahlmann, in his excellent German translation and csinpletion of 

 my Asie centrale, Th. ii. S. 60. 



(S 94 ) p. 321. Hsec de temperie seris, qui terram late circumfundit, ac in 

 quo, longe a solo, instrumenta nostra meteorologica suspensa habemus. Sed 

 alia est caloris vis, quern radii solis nullis nubibus velati, in foliis ipsis et 

 fructibus maturescentibus,magis minusve coloratis, gignunt, quemque, ut egregia 

 demonstraut experimenta amicissimorum Gay-Lussacii et Thenardi de com- 

 bustione chlori et hydrogenis, ope thermometri metiri iiequis. Etenirn locis 

 planis et montanis, vento libe spirante, circumfusi seris temperies eadem esse 

 potest coelo sudo vel nebuloso ; ideoque ex observationibus solis thermometricis, 

 nullo adhibito Photometro, haud cognosces, quam ob causam Galliae septen- 

 trionalis tractus Armoricanus et Nervicus, versus littora, coelo temperato sed 

 sole raro utentia, Vitem fere non tolerant. Egent enim stirpes non solum 

 caloris stimulo, sed et lucis, quse magis intensa 'ocis excelsis quam plains, 

 duplici modo plantas movet, vi sua turn propria, turn calorem in superficie 

 earum excitante. (Humboldt, De distributions geographica plautarum, 1817, 

 pp. 163164). 



C 395 ) p. 321. The work last quoted, pp. 156161; Meyen, in his 

 "Grundriss der Pflanzengeographie," 1836, S. 379467; Boussingault, 

 "Economic rurale," T. ii. p. 675. 



C 98 ) p. 322. I subjoin a Table, exhibiting, in a descending scale, the 

 capability of different places in Europe for the production of wine. See my 

 "Asie centrale," T. iii. p. 159. The numerical data for the banks of the 

 Rhine and the Main are given in addition to those for the places referred to 

 in the text of Cosmos. A comparison of Cherbourg and Dublin with places 

 in the interior of Europe, shews that, with but little difference of temperature, 

 so far as the indications of the thermometer in the shade are concerned, the 

 question of maturity or immaturity of fruit is determined by the habitual 

 serenity or cloudiness of the sky. 



The great accordance in the distribution of the annual temperature 

 throughout the different seasons of the year in the vallies of the Rhine 

 and the Main, tends to confirm the accr.rrcy of the ob. :r niions. Tho 



