THE FARMER'S MAGAZINE. 



29 



those cells close to the vascular tissue. A larger 

 proportion of such cells would, of course, occur in 

 the thick body than at the point of the root. 

 A considerable portion of the azotic substance 

 being found in the vascular tissue, it struck me 

 that the law of distribution for the other proxi- 

 mate principles of the root might not be the same 

 as that for sugar. With the view of determining 

 this point, I made, during the last Autumn and 

 Winter, the following experiments: — 

 I. — A root of long red mangel wurtzel, weighing 

 9lbs. 15oz , and measuring 19 inches in length, 

 had five cross sections cut from it, which gave, 

 when dried, the following results per cent. : — 



^°/;'^ Water, 

 matter. 



1. Segment of crown, half-inch 



thick, . . . .11.64 88.36 



2. Segment of body immediately 



below the crown, . . 11.09 88.91 



3. Segment of body three inches 



below section No. 2, . . 10.28 89.72 



4. Segment of body four inches 



below section No. 3, . . 11.17 88.83 



5. Points of root or forkings, . 12.85 87.15 

 II. — A root of white Silesian, or sugar beet, weigh- 

 ing 61bs. lloz., and measuring 14 inches in 

 length, similarly cut, gave per cent. : — 



S«/;d Water, 

 matter. 



1. Segment of crown, . . 7.55 92.45 



2. Segment of body, half-inch 



below crown, . . . 8.75 91.25 



3. Segment of body, taken three 



inches below No. 2, . . 10.45 '89.55 



4. Segment of body, taken three 



inches below No. 3, . . 11.55 88.45 



5. Point of root, two inches long, 12.13 87.87 

 According to these results, the maximum amount 



of soHd matter is in the thin part of roots, which, 

 according to Rehring, contains but little sugar. 

 When the quantity of sugar is very considerable, 

 the maximum may, however, be in the thickest 

 part of the root. 



The relative diminution of solid matter, as the 

 size of an organ increases, appears to be a uni- 

 versal law within certain limits ; and the proportion 

 of nitrogen follows the same law. The young 

 buds, just before bursting into leaf, contain more 

 solid matter and nitrogen than when fully unfolded. 

 In the case of cabbage, I have found, in two 

 instances that I tried the experiment, that the 

 increase of water, from the young heart leaves to 

 the external ones, was quite regular. Large roots 

 sometimes appear to form an exception to this law 

 by containing more nitrogen than the smaller 

 roots. Part of this nitrogen is often, however, 

 derived from nitrates and ammonia — the quantity 

 of the former being always greater in large than 

 in small roots. It would appear, too, that part of 

 the azotic bodies is expended during the produc- 



tion of the sugar, and that, consequently, the less 

 sugar that is produced, the less of the azotic bodies 

 will be lost. 



Being desirous of ascertaining how far this 

 gradual increase in the relative amount of solid 

 matter, towards the narrow parts of the roots, 

 would influence the difference between large and 

 small roots, which former experiments, made in 

 the Museum of Irish Industry, had established, I 

 recently undertook to make a new series of deter- 

 minations, not upon a segment of the root as 

 before, but upon the whole root. Although it is 

 now universally admitted that large roots contain 

 more water than small ones, yet it seemed to me 

 to be worth incurring the labour of this new series 

 of determinations, if for no other purpose than to 

 ascertain the actual condition of our green crop 

 husbandry as regards quality. The results of this 

 inquiry, which extended to nearly all the kinds of 

 root crops now cultivated in Ireland, and in which 

 much care was taken in getting average samples, 

 will be found in the annexed table. Besides the 

 actual determinations of water and solid matter, 

 the results of which are given in the table, I made 

 a series of determinations of the density of a great 

 number of other roots, by a process to be de- 

 scribed further on. So that, although but two 

 roots from each locality were dried, these were 

 selected as representing the average, as determined 

 by the density of, perhaps, in some cases, twenty 

 roots. The table may, consequently, be considered 

 to express the present average quality of Irish- 

 grown roots, and will serve as a standard by which 

 to determine the future improvements in the qual- 

 ity of our green crops, for which, indeed, there 

 appears to be much room. Hitherto, all the efforts 

 of husbandmen seem to have been directed to 

 quantity and none to quality. This is abundantly 

 proved by the circumstance that the only test 

 recognized at shows of agricultural produce, for de- 

 termining, the comparative merits of the specimens 

 of turnips, &c., exhibited, is weight. It is to be 

 hoped that henceforward some better test than this 

 will be introduced, and that prizes be awarded for 

 improving green- crop husbandry, and not for de- 

 teriorating it, as the present forcing system but 

 too often tends to do. 



However important the object above mentioned 

 may be, it was not the immediate one I had in 

 view in making this new series of determinations. 

 That object was connected with the subject of this 

 paper, and which I shall now enter upon. 



An examination of the table alluded to, shows 

 that, although large roots almost invarialjly contain 

 less solid matter than small ones, thus confirming 

 the results of former experiments made upon seg- 

 ments and not upon the whole root, equal differ- 



