614 EXPERIMENT STATION RECORD. 



(2) Continue the addition of decinormal iodin solution till a tinge of yellow 

 color obtains. The number of cubic centimeters decinormal iodin added mul- 

 tiplied by 0.0064=sulphur as thiosulphate and by 0.0056=lime (CaO) in com- 

 bination as thiosulphate. Starch paste or paper may be used in (1) and (2) 

 but the addition of starch renders filtration of (2) difficult to proceed to (3). 



"(3) The fluid used in (2) is filtered through double filter paper and washed 

 with cold water. To the filtrate barium chlorid and a few drops dilute hydro- 

 chloric acid are added, and the whole allowed to stand all night in the cold. 

 Barium sulphate is filtered off, washed, dried, ignited, and weighed. The weight 

 obtained multiplied by 0.1373=sulphur present as sulphate and sulphite. The 

 sulphur multiplied by 1.75=lime equivalent to sulphur as sulphate and sul- 

 phite. 



"(4) Ten cc. of the diluted mixture is diluted with about 25 cc. water and is 

 shaken up in a separating funnel with 10 cc. carbon bisulphid, and allowed to 

 separate. The carbon bisulphid is drawn ofC into a tared Erlenmeyer flask. The 

 diluted mixture in the funnel is again extracted with 10 cc. carbon bisulphid 

 and finally with two lots of 5cc.each — the carbon bisulphid after extraction being 

 added to that already in the tared flask. The carbon bisulphid is now removed 

 by placing the flask in warm water, and the flask and contents dried to constant 

 weight at a low temperature (not exceeding 70° C). The sulphur obtained is 

 free sulphur. 



"(5) To 10 cc. of the diluted mixture, about 6 or 8 gm. sodium peroxid is 

 added to oxidize the mixture, which is allowed to stand a few minutes. Fifty 

 to 75 cc. water is added, and then hydrochloric acid, cautiously, till the solution 

 clears up. Add a few drops of potassium iodid solution (15 gm. KI in 100 cc. 

 water) to reduce the higher oxids (of chlorin) — boil off the excess of iodin — 

 dilute with water to about 200 cc. and precipitate sulphur as BaSO^. Filter, 

 dry, ignite, weigh, and calculate to sulphur by multiplying weight of precipi- 

 tate by 0.1373. This gives total sulphur. 



"(6) To another 10 cc. aliquot of the diluted mixture, decinormal iodin solu- 

 tion is added as previously described till sulphids and thiosulphates are decom- 

 posed as at (1) and (2). Filter sulphur off through double-filter paper. Make 

 filtrate ammoniacal, and determine the lime by precipitation with ammonium 

 oxalate. This gives total lime. Calculations: (a) Sulphur obtained at (5) — 

 [sulphur (4)+sulphur (3)+sulphur (2)]=sulphur as hydroxyhydrosulphid 

 and disulphid=a. (b) Lime obtained at (6) — (lime calculated at (3)+lime 

 calculated at 2 ) =lime as hydroxyhydrosulphid and disulphid= &. Let a?=lime in 

 combination as hydroxyhydrosulphid then 6— d?=lime in combination as disulphid. 

 Further, a- X 0.5714 will be the sulphur in combination with x lime as hydroxyhy- 

 drosulphid and 6— a? X 1.1428 the sulphur with 6— a? lime as disulphid. Then 



xX0.5714+(6 -a;) X1.1428=a, 



z-( 6X1.1428)-a 

 0.5714 



from which h—x is found." 



The technical method for manufacturing dicyanamid from lime nitrogen 

 from the standpoint of chemical kinetics, G. Grubk and P. Nitsche (Ztschr. 

 Angew. Cliem., 21 {19U), No. 50, Aufsatsteil, pp. S68-S78, figs. 4).— A discussion 

 of the methods and the results of some experimental work in this direction. 



Formation of furfurol from wood during the steaming process, E. Heuseb 

 (Ztschr. Angew. Chem., 27 {19H), No. 100, Aufsatzteil, pp. 654, 655).— All 

 furfurol obtained from straw or wood which is undergoing a process of steaming 

 at 4 atmospheres originates from the pentosans which the substance contains. 



