Analyses of Ashes of Plants. 179 



Table 5. — Composition (in 100 parts) of the Ash of Turnip Tops. 



No. of Spec. 



82 



83 



84 



85 



77 



86 



Mean 

 of the six 



Variety. 



Skirving's 

 Swede. 



Skirving's 

 Swede. 



Dale's 

 Hybrid. 



Dale's 

 Hybrid. 



Skirving's 

 Swede. 



Green-top 

 White. 



Sjiecimens. 



Per Centage 1 

 of Ash ./ 



1-97 



1-95 



1-19 



2-25 



1-61 



1-82 





Silica . . 

 Phosph. Ac. 

 Sulph. Ac. . " 

 Carb. Ac. . 

 Lime . 

 Magnesia . 

 Perox. Iron 

 Potash . . 

 Soda . _ . 

 Chlo. Sodium 

 Chlo. Potass. 



8'04 

 4-85 



10- 36 

 6-18 



28-49 



2- 62 



3- 02 



11- 56 



12- 43 

 12-41 



1- 14 

 6-21 



12-20 

 12-97 



30-38 

 3-18 

 •66 

 20-79 



10*31 



2- 09 



1-26 

 4-58 

 6-71 



13-82 



35-10 

 1-75 

 -61 



13-53 

 4-60 



18-02 



7-35 



11- 70 

 6-99 

 6-10 



24-27 

 3-57 

 3-09 



12- 35 



22*70 

 1-84 



4-11 

 6-54 

 6-50 

 6.16 



23-99 

 2-92 

 1-90 



20-36 



17-69 

 9-77 



2- 05 



3- 15 

 7-83 



14-64 

 28-73 

 2-85 

 -80 

 12-68 



10-67 

 16-56 



3-99 

 6-17 



8- 43 



9- 98 

 28-49 



2-81 



1- 68 

 15-21 



2- 84 

 15-30 



5-04 



Total . 



99-96 



99-93 



99-98 



99-96 



99-94 



99-96 



99-94 



From the first of these tables we may learn that there is a 

 certain and somewhat close resemblance between the composition 

 of the ash of one turnip-bulb and another. The quantity of 

 phosphoric acid is seen to be tolerably constant, and the alkalies, 

 together, make up very nearly the same amount. In our last 

 report we remarked that there did not appear in the wheat crop 

 which we had examined, any corroboration of the doctrine which 

 supposes substitution of one alkali for another. The present 

 analyses would favour the opposite conclusion, for the deficiency 

 of potash in some specimens is to a certain extent made up by a 

 greater quantity of soda.* 



The second table exhibits far wider differences in the compo- 

 sition of the ash, the phosphoric acid of one (Specimen 85) being 

 double that of some others, &c. &c. We were prepared for this. 

 In the growth of plants of this description, the construction of the 

 materials is supposed to go on in the leaves, from which the vege- 



* To those who are unacquainted with the laws of chemical combina- 

 tions, it may be necessary to remark, that soda and potash would not 

 replace each other in equal quantities. The saturating power of each hase 

 is represented by a particular number, thus :— 31 parts of soda (omitting 

 fractions) will go as far as 47 of potash in any application as an alkali— in 

 destroying the properties of an acid for instance. The same holds good in 

 regard to plant-ashes. It is not therefore absolutely correct to compare the 

 united weight of these bodies in one case with the same weight in another 

 specimen. 



N 2 



