RECENT WORK IN AGRICULTURAE SCIENCli 



CHEMISTRY. 



The determination of sulphur and phosphorus in plant substances, C. P. 



Beistle {Jour. Amcr. (_'hcm. Soc, 24 {1H02), No. 11, pp. 109S-1100). — Comparative- 

 tests of 8 different methods on cotton-seed meal, timothy hay, and egg albumen are 

 reported. The results show that the fusion method with ])otassium hydroxid and 

 potassium nitrate gave the highest results for sulphur in all three of the substances 

 examined. "The amount of suljihur in the ash of the vai'ious samples is so low that 

 it gives no indication of the total amount of sulphur present, showing that the greater 

 portion is driven off by ignition. The sulphur obtained l)y Ixjiling with potassium 

 hydroxid solution, with subsecpient oxidation with chlorin, gave only half the sul- 

 phur found by the fusion method. The sulphur found by ignition in the bomb 

 calorimeter is about the same in amount as that found by combustion in a stream of 

 oxygen and absorption of the products of combustion in a hydrochloric acid solution 

 of bromin, but i's still considerably less than is obtained by fusion." It was found 

 that special precautions were necessary in order to secure the complete oxidation of 

 the sulphur. 



"The fusion method gave slightly more phosphoric acid than the ash in the case 

 of the cotton-seed meal, but jiractically the same for the timothy hay and egg albu- 

 men. This would indicate that in the substances examined, the phosphoric acid was 

 volatile to a very slight extent, if at all. Boiling with potassium hydroxid solution 

 and treating with chlorin gave results so low that this method may be discarded for 

 the analysis of this class of bodies. The phosphoric acid found by ignition in the 

 bomb calorimeter was slightly less than by fusion, and this difference was probably due 

 to mechanical loss of the smaller particles of the glassy slag which contained almost 

 all the phosi>horic acid. The amount of phosphoric acid ol)tained from the hay by 

 boiling with nitrohydrochloric acid was practically the same as found by fusion or 

 incineration. When the cotton-seed meal was treated in this way only al)0ut half of 

 the phosphoric acid present was obtained." 



Investigations are reported which indicate that this latter fact is jiossibly due to 

 the phosphoric acid being in organic combination, which is not Ijroken down by l)oil- 

 ing with strong nitrohydrochloric acid. 



The determination of sulphur and phosphorus in organic materials, H. C. 

 Sherman {Jour. Aitwr. Chnn. Soc, 24 (1902), Xo. 11, pp. 1100-1109).— Compar'mms 

 of the l)omb calorimeter and nitric acid methods (with compressed oxygen), sodium 

 peroxid-hydroxid, for sulphur and the i-alorimeter, sodium carbonate, and sulphuric 

 acid ammonium nitrate methods for phosphorus, on dried lean beef, milk curd, coagu- 

 lated white and yolk of eggs, wheat )>ran, and dried beans are reported. The conclu- 

 sions reached were as follows: 



"For the determination of sulphur the method of combustion in compressed 

 oxygn is preferred. Equally good results were obtained by the hydroxid-peroxid 

 method, but the manipulation is less convenient. The nitric acid method as used 



gave low results. 



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