1922] EATON—SULPHUR CONTENT OF SOILS 51 
(5) observed a darker green in the foliage of rutabagas, parsnips, 
and beets fertilized with sulphur than in the check experiments. 
An experiment was planned to try to determine the relation between 
the sulphur and the chlorophyll content of the plants. STowELL’s 
evergreen sweet corn and mammoth red clover were grown in 
ordinary 12-inch flower pots. Thirty-six pounds of sand were 
added to each pot. For series 1, 2, and 3 pure quartz sand was 
used; for series 4, 5, 6, 7, and 8 a fine grade of torpedo sand sifted 
free from stones and coarse material was used. Sulphur was added 
to the sand, as shown in table IX. The figures in the table mean 
that sodium sulphate and flowers of sulphur were added in such 
amounts as to give the same amount of sulphur as contained in 
TABLE IX 
AMOUNT OF SULPHUR ADDED TO SAND CULTURES OF CLOVER AND 
R 
Series shade = sad sooner. a woe te oy og 
Wiel ene a seater Bee te LN Nise Ca ku ee eek Co PC Ee ee ea 
Bis in oes EN aa WN ee ae fos + SoM tea Oye aca airy. oe aranes 
SP ech sank Ma aca s ok anace TO Ee a oa Oe eae es ade © oe Vin re Pees 
Meta ene ee es Cates hace vir con Crs Seis Penn an ee en De: 
Bre ee S00 5 ME Lea a ee 
De iss otek ia pie SO Tae ph etre Pale Cen 
Pees Ga BOO Se ea ee cua Oe a cia os 
Deir dare eR eUw Ges eae ey atee ee ue ee 500 
100, 300, and 500 pounds of gypsum per acre, or two million 
pounds of sand. Each series was run in triplicate. 
he gypsum and flowers of sulphur were thoroughly mixed with 
the sand at the time the pots were filled. The sodium sulphate was 
added in solution in three applications. The corn was harvested 
sooner than had been planned, and received only two applications 
of sodium sulphate. The sodium sulphate series in the case of the 
corn, therefore, received two-thirds of the amount given in the 
table. In addition lime was added at the rate of 1000 pounds per 
two million pounds of sand. One week after the cultures were 
Started 1 gm. of ferric chloride was added to the sand of each pot. 
The corn was planted February 7. It had previously been placed 
between moist filter paper, and at the time of planting all the 
