520 EXPERIMENT STATION RECORD. 



" Tlie sulphur content of a number of . . . common farm jtroducts ... is 

 much larger than found by Wolff In the ash from such products. 



"The amount of sulphur trioxid removed by crops is considerable, being 

 equal in the case of average crops of cereal gi-ains and straws to about two- 

 thirds of the phosphorus pentoxid removed by these crops; the grasses of 

 mixed meadow hay remove quite as much sulphur as phosphorus, while the 

 legume hays may approach, and in the case of alfalfa, even exceed in this 

 respect. Members of the Cruciferfe, as the cabbage and turnip, are heavy 

 sulphur-using crops and may remove two to three times as much sulphur 

 trioxid as phosphorus pentoxid. An average acre crop of cabbage will remove 

 about 100 lbs. of sulphur trioxid." 



It is estimated that the gain from precipitation in the region of Madison 

 does not amount to more than 15 to 20 lbs. per acre annually, while the loss 

 in drainage amounts to about 50 lbs. per acre yearly. 



" The fact that common crops remove from the soil considerable quantities 

 of the element sulphur, while the compensating factor of supply from the 

 atmosphere is very probably offset by the losses which the land sustains by 

 drainage, makes it apparent that for the maintenance of a permanent supply 

 of sulphur in the soil, this element must be added systematically either as a 

 constituent of commercial fertilizers, or with the farm manure." 



The method used in the determination of sulphur in soils was as follows : 



" Ten gm. of soil* were placed in a 100 cc. niclvel crucible, moistened with 

 water, about 10 gm. of a weighed 20 gm. portion of sodium peroxid added, 

 and the mixture thoroughly stirred with a platinum rod. The crucible was 

 placed over an alcohol flame and heated moderately until the mass was dry. 

 The remainder of the sodium peroxid was then added, the cover placed on the 

 crucible, strong heat applied until the mass melted, and kept in this condition 

 for 10 minutes. It was then allowed to stand over a lower flame for 1 hour. 

 The crucible was removed, cooled, placed in a 600 cc. casserole, hot water 

 added and the fused mass removed. It was neutralized with hydrochloric 

 acid and then further acidified with 10 cc. of hydrochloric acid. The volume 

 was made up to about 450 cc. and boiled for 15 minutes, or until no imdecom- 

 posed portion of the fused mass remained on the bottom. The covered casserole 

 was allowed to stand on the steam bath over night, filtered through a ' nutsche ' 

 and the residue thoroughly washed with successive small portions of hot water. 

 The filtrate and washings, if over 500 cc, were evai^orated below that volume, 

 refiltered, and the volume made up to 500 cc. Aliquots of 250 cc. each were 

 heated to boiling, barium chlorid added, boiled for 5 minutes, and set aside on 

 a steam bath for 24 hours. The volume was not allowed to decrease as silicic 

 acid may be precipitated if much evaporation takes place. After standing for 

 this length of time the barium sulphate was filtered off, washed, ignited and 

 weighed. In the determinations made by this method the precipitate was free 

 from silica as demonstrated by the hydrofluoric acid test." 



This method gave considerably higher results than the official method and 

 somewhat higher than the nitric-acid-bromin method (modified) of Van Bem- 

 melen. 



The sulphur requirements of farm crops in relation to the soil and air 

 supply, E, B. Hart and W. H. Peterson {Jour. Amer. Chem. Soc, 33 {1911), 

 No. 4, pp, 5.^9-564; abs. in Jour. Chem. Soc. [London], 100 {1911), No. 583, II, 

 p. 431). — This is an account of the investigations noted above. 



Catalytic fertilizers in the culture of beets, G. Bertrand {Rev. 8ci. [Paris], 

 .',9 {1911), I, No. 22, pp. 673-680).— The author shows the general distribution 

 of manganese in plants and maintains that this substance is essential to the 

 oxidizing action of oxydases, laccases, etc., which in turn is essential to the 



