134 
Transactions of the Boyal Society of South Africa. 
excess over such amount is calculated as sodium carbonate. By ''total 
alkaline salts " is understood the sum of the sodium chloride, carbonate, 
and sulphate. 
7. Determination of Total Lime. — To an aliquot part of the soil solu- 
tion two or three drops of rosolic acid are added ; then dilute ammonia by 
means of a dropping tube and a sufficiency of ammonium chloride to 
redissolve any precipitated magnesia, after which the liquid is warmed, 
20 c.c. of 4 per cent, ammonium oxalate solution are added, and the deter- 
mination is further conducted exactly as in the extraction of the soil by 
hydrochloric acid. It may, however, be found preferable, especially when 
the quantity of lime is small, to dissolve the oxalate precipitate in dilute 
N 
sulphuric acid and determine its amount by titration with ^qq potassmm 
permanganate. 
8. Calciujn and Magnesium Carbonates and Sulphates. — Any carbon 
dioxide which may be present in excess of that combined with soda, as 
sodium carbonate, is calculated in the first instance as calcium carbonate. 
Should this not yet account for all the carbon dioxide, the rest of the 
latter is calculated as magnesium carbonate ; on the other hand, if there 
still remains an excess of lime unaccounted for, it is calculated as calcium 
sulphate. Any excess of sulphuric oxide which may still remain is 
assigned to magnesia."" 
Herbert. 
According to the methods outlined above, determinations of alkaline 
salts were made in three samples of surface soil from Douglas in the 
Division of Herbert. These determinations resulted as follows t : — 
DOUGLAS (HEEBERT DIVISION) SOILS. 
Sodium 
Sulphate. 
a5 
S 
Total Alkaline 
Salts. 
Calcium 
Sulphate. 
a • 
a a5 
Total Soluble 
Salts. 
Numb( 
Sodiu: 
Chlori 
Sodiu 
Carbon 
Calci' 
Carbon 
Magnes 
Sulpha 
Magnes: 
Carbon 
Calcu- 
lated. 
Found. 
1 
% 
•006 
% 
% 
% 
•006 
% 
•021 
/o 
•028 
/o 
% 
% 
•055 
% 
•048 
2 
•005 
•002 
•007 
•001 
•038 
•046 
•060 
3 
•006 
•003 
•009 
•035 
•003 
•048 
•056 
* Should there be more lime or magnesia, or both, than required for the sulphuric 
oxide present, these are in such cases calculated as chlorides, a corresponding deduction 
from the sodium chloride being made. 
t The results are stated in percentages, and, except where the contrary is indicated, 
blanks in the tables denote absence of the particular substance specified. 
