ir 6 Colorado Experiment Station 
The sulfur was determined in the same manner as the phosphorus, ex¬ 
cept that ordinary gas could not be used, either in evaporating or igniting. 
I used electricity for the former and gasolene for the latter purpose. The 
magnesic oxid was dissolved in hydrochloric acid. If the magnesic oxid 
be heated in the muffle, care must be exercised that it does not attain too 
high a temperature or a loss of sulfuric acid may occur. 
The manganese was determined colorometrically. The wheat was des¬ 
troyed by nitric acid as in the other instances. The combustion was tom- 
pleted in the muffle, the residue taken up with sulfuric acid and filtered. 
Any carbon that had escaped combustion was burned off and the residue 
dissolved in sulfuric acid and added to the first filtrate. The solution con¬ 
tained about 5.0 percent of sulfuric acid. A few* milligrams of silver sul¬ 
fate Were added as a catalytic agent. A few grams of ammonic presulfate 
were then added and the solution heated in a boiling water bath so long 
as the color deepened. 
THE ANALYSIS OF WHEAT PLANTS AND WHEAT STRAW 
The analyses of these substances present some difficulties. To deter¬ 
mine the ash, I took 10 grams of the ground straw or plant, charred thor¬ 
oughly and extracted three times with boiling water, then burned out the 
carbon as completely as possible and extracted again with waten as thor¬ 
oughly as possible. The residue was ignited and weighed as insoluble ash. 
This portion is seldom white and an examination under the microscope 
shows the siliceous outlines of the cells inclosing particles of carbon. The 
water-soluble portion of the ash contains from 25 to 30 percent of its weight 
of silicic acid. The terms soluble and insoluble ash mean but little in this 
case. Their sum gives the total ash, less the phosphorus, which in this 
process may be so good as wholly lost by volatilization. Hydrochloric acid 
will extract from the insoluble ash obtained in this way about 0.1 percent 
of the weight of the straw. 
For the analysis proper, I took 100 grams of the ground straw; and 
proceeded as above, except that I extracted thei charred mass with hydro¬ 
chloric acid, as it extracts less coloring matter than water. The charred and 
extracted mass was pulverized, the carbon burned out as far; as possible 
and the residue again extracted with hydrochloric acid. This residuevwas 
ignited and considered as pure silica, though it was not white. The,hydro¬ 
chloric acid extracts were evaporated to d.ryness to separate silicic acid 
that had gone into solution. The weight of this was added to the 
insoluble silica and theirl sum was considered as total silica. The hydro¬ 
chloric acid solution was made up to 250 c.c. An aliquot part, from 60 to 
100 c.c. according to the quantity of soluble ash found in the sample, was 
taken for further manipulation. A few cubic centimeters of a ten-percent 
solution of ammonic phosphate were added and the bases precipitated by 
the addition of ammonia, to which a little ammonic sulfid was added to 
carry down traces of manganese and, possibly, zinc. The manganese and 
zinc were present in such small amounts that no further attention was paid 
to them at this time. . , \ 
