1922] HALL—ALFALFA 405 
He states that in any dry fusion method there is some sulphur 
being lost in the fumes no matter how carefully the fusion is made. 
No experiments were made to test this statement, but the variation 
in results obtained from a number of analyses of the same sample 
leads one to believe that even with the official method some of the 
sulphur is not secure. It seems probable that in all determinations 
of the sulphur content of plant materials to date, the results are 
low because of the loss of sulphur in fusion. Some difficulty was 
experienced in controlling the fusion so as to prevent the reaction 
proceeding too rapidly. If the reaction becomes too violent, smoke 
is evolved in considerable quantities, and results obtained under 
these conditions are uniformly higher than those obtained when 
the fusion takes place at a moderate rate. At first the samples 
were considered lost although no flashing took place, but later 
these samples were saved, and in every case showed a higher value 
than those that were controlled perfectly, and agreed very closely 
in the final result. The rate of fusion may have a great deal to 
do with the amount secured from the sample. This point will be 
studied more extensively later. The evidence is that all the sulphur 
was not being obtained from the samples. Kocu advocates the 
use of perhydro, a very concentrated hydrogen peroxide, in the 
determination of sulphur, but unfortunately this substance has not 
been on the market since the war, as Germany was the sole manu- 
facturer. Oxson (8) used the Parr bomb, and, when certain precau- 
tions are followed, claimed for it advantages in speed and in 
assurance against losses of sulphur. Modification of the method 
is reported in connection with more recent determinations (9, 10). 
All the determinations were made on the air dry material, 
_and the percentage of sulphur calculated to the oven dry weight 
_ as follows: 
Number of grams in aliquot........ ee 1.25 
Weight of BaSO, obtained. ........ 0.0328 gm. 0.0329 gm. 
Percentage of sulphur in BaSQ,..... ee ee eee 
Percentage of moisture in sample.... 5.82 5.82 
Percentage of sulphur in sample..... 0.382 0. 382 
The Benepict method (4) was tried, but proved very unsatis- 
factory because of the extreme tendency of the material to sputter 
