for iht Purpofe of affording Sugar. 289. 



afl^, is often very fweet, while the upper part, not covered by the earth, and thus expofed to 

 adion of light, is not in the leaft fweet, but even polTeffes a bitter tafte. 



20. The Very reverfc holds good with refpe6t to fruits, more efpecially from trees, at leaft 

 for the moft part, if not with all of them. In this part of the plant the matter of light caufes 

 an increafe of faccharine matter; and its influence is direftly oppofite to that which it exerts 

 on the roots. I think it fuperfluous to offer proofs of this phenomenon, as every amateur 

 of gardening knows that the pleafant and fweet tafte of fruits from trees is moft certainly 

 produced by bringing them to a place where they are moft expofed to the fun. Branches 

 of one and the fame tree yield fruits of different agreeable flavour and fweetnefs, according 

 as they are in various degrees adted upon by light; fo that the fruits from fliaded branches 

 are much inferior to thofe that are not ftiaded. 



21. It is no lefe eafy to prove, that by the abforption of light in the roots, the extraEl'tve, 

 paponaceousi snA farinaceous principles are increafed, which give to the juice of the root the qua- 

 Itty of leaving, on infpiflation by fire, a tenacious, pulpy mafs, which, on account of its con- 

 fiftence and other properties, throws great, and often infurmountable, diiHculties in the way 

 of the feparation of the fugar, and likewife makes it impoflible to produce a fyrup of a pure 

 fweetnefs. 



22. To be thoroughly convinced of this, nothing more is required than to examine a 

 runkelriibe, a carrot, a parfnip, a parfley-root, or any other root, in fuch a manner, that the 

 part above the ground may be compared with the part that remained beneath. It will then he 

 found, that the latter not only contains more juice than the former, but, in general, alfo that 

 both thefe feveral parts are materially different as to texture, weight, compadlnefs, and co- 

 lour. The fweetnefs of the roots covered by earth may be diminiflied, only by caufing the 

 light to aft on the upper uncovered part. By fuch procedure a confiderable change in the 

 faccharine matter, and other conftituent parts, even in the lower part of the root, is 

 effeded. 



23. Since the chemical analyfis, as well as the phyjiohgy of plants, evinces that all this de- 

 viation in the nature of the parts of one and the fame plant, accordingly as it ftands above 

 or below the ground, is imputable to the increafe of thofe of its ccnftituent parts which, 

 taken together, impart to the infpiffated juice of the root the property of refifting the fepara- 

 tion of the fugar by cryftallization; it follows from thence, if applied to the runkelriibe, that 

 by preventing, in the beft poffible manner, the accefs of the matter of light to that part of 

 the root which lies under the heart, or the place from which the leaves take their rife, the 

 runkelriibe muft be produced, not only richer in fugar, but alfo containing lefs of fuch other, 

 parts as impede the feparation of the faccharine matter. 



24. Upon the full proof of thefe affertions it is that my method of cultivating the run- 

 kelriibe is eftablifhed. I found it perfeftly confirmed and eftablifhed by experiments, partly 

 in my own culture, partly by comparing the faccharine contents of fuch roots as had grown 

 in various places, and under different management. I therefore affirm that the runkelriibe 

 only which is produced in the manner 1 have here indicated, will be fo rich in fugar, and fb 



pOOB 



