810 REPORT—1904. 
IIydrogen peroxide has long been recognised as a product of oxidation, but so far 
as the authors are aware the formation of nitrites and nitrates has not before been 
noticed. 
The experiments have been carried out as follows:—A platinum dish contain- 
ing the oxidisable substance and pure distilled water was placed in an empty 
desiccator, supported over a large dish of sulphuric acid and covered with a bell- 
jar to prevent free access of outside air. A second exactly similar apparatus was 
put up as a control, the platinum dish containing water alone. The two were 
allowed to stand side by side in sunlight for eight days and their contents then 
tested. The results obtained are set forth in the following table. It will be observed 
that on no occasion did the control experiment show the presence of either 
ammonia, nitrite, or nitrate. 
Substance in Dish Ammonia 
| | Nitrite Nitrate | 
| : Je eS OES Sieg AE 
| UAV ALCL 0 Be hs oe cstwt! Feb ied cape Nil | Nil Nil 
Iron . : ; : , ; ‘ Some | Nil Nil 
Pe Abr iee ; , , . : : 5 Some le NG Some 
| Magnesium j : : : j , Some | Some Little 
| Manganese chloride + sodium carbonate . | Small quantity, Much Some 
| Ferrous sulphate + sodium carbonate  . Much | Some Much 
Negative results were obtained with tin, stannous hydroxide (stannous chloride 
+ sodium carbonate), cuprous chloride, cuprous hydroxide (cuprous chloride 
+ sodium carbonate), and tartaric acid. 
Sunlight favours this autoxidation; it is doubtful, in fact, whether it takes 
place in the dark. 
The reaction apparently goes on in soils. A soil rich in humus was washed to 
remove ammonia, nitrites, and nitrates as far as possible; it was then placed into 
the apparatus for a few days. All three substances were found to have formed 
in very distinct amounts. 
7. The Chemical Composition of Different Varieties of Mangels. 
By T. B. Woop, J.A4., and R. A. Berry, 7.0.0. 
A considerable number of well-known varieties of mangels were grown on the 
University Farm at Impington, near Cambridge, on a medium loam soil, and at 
four stations in Norfolk, and one in Bedfordshire. Two seasons’ crops have already 
been harvested and examined. Samples were taken in the form of horizontal 
cores through the greatest diameter of the root, and at least fifty roots were cored 
from each plot. The dry matter was determined by drying at about 65° C. to 
constant weight duplicate samples of fifty cores each. These were then ground 
and used for the determination of nitrogen by Kjeldabl’s method (salicylic acid 
modification, as the roots contain nitrates), 
The sugar was determined in the juice expressed from the pulped cores. The 
juice was first clarified with basic lead acetate, and then polarised, inverted by 
Clerget’s method, and polarised again. It was found that in the autumn, when 
the roots were examined, the sugar was nearly aJl cane sugar with ‘] to ‘5 per 
cent. of dextrose. 
The two years’ systematic examination shows clearly that mangels, leaving 
out a few new and peculiar varieties, may be divided into four classes, each with 
definite characters. 
Group I—- Yellow Globe.—Yellowish skin, nearly white flesh; a very large 
cropper on all the soils on which it has been tried. Low percentages of dry 
matter and sugar; average percentage of nitrogen, less than one-third of which is 
roteid. 
4 The various seedsmen’s strains, such as Sutton’s Prize Winner, Webb’s 
Smithfield, Carter's Windsor, are all practically identical. ; 
Grovur II.— Golden Globe.—Orange skin, deep yellow flesh; a very fair 
cropper on all the soils on which it has been tried. High percentages of dry 
