1020] 



AGRICUITUHAL CilfiMtSTRY — AGROTECHNY. 



617 



lo 1 iKTcciit for a more dclicsite product reseiubliiig Iiomoinade jelly. The liiiiit- 

 iiiir, oiitiiiitini, and iiKi.xiiiiuin values for acidity (calculated as suli)liuri(' acid) 

 Were found to be O.JT, 0.8, and 0.5 per cent, respectively. 



With an apple juice of 0.43 per cent acidity and 1.25 per cent pectin content, 

 .ielly with the best texture for commercial purposes was obtained with a sugar 

 content of 5 lbs. per gallon of juice, although the flavor of the lot containing 

 G lbs. per gallon was somewhat better. It was also found that a jelly of 

 sati.«ifactory texture and quality can be made from apple juice by using 1 lb. 

 of sugar per gallon for every degree of the Brix hydrometer reading. 



As a quantitative metho«l of determining pectin the author iises 10 cc. of 

 liltered juice and 180 cc. of alcohol, adding the juice drop by drop from a 

 pipette with I'reciuent stirring. The precipitate is either filtered directly on a 

 weighed CJooch crucible, dried, and weighed, or is filtered, dissolved in boiling 

 distilled water, evaporated to dryness, heated two hours at 70° C. in vacuo, 

 weighetl, ashed, and reweighed. By observing the precipitation of the pectin 

 as the juice is slowly run into the alcohol in the above proportions, an indica- 

 tion of the amount of pectin may be obtained, the precipitate forming a 

 cohesive gummy mass with over 1 per cent of pectin and only a flocculation 

 if the amount is less. 



The chemistry of leatlier, L. Egl^ne (La Chimie du Cuir. Paris: H. Dunod 

 and /•;. Pinut, 1<)19, pp. XV-{-136, figs. 9).— This book treats of the chemical 

 changes involved in the preparation of hides for tanning, in the tanning process 

 proper, and in the finishing of the leather. The general processes involved in 

 the making of leather are outlined in a preface by G. Jossier. 



The chemistry of wood, I. B. Waksicu (Ztschr. Angeio. Chem., 33 {1920), No. 

 SO, Aufsatzt., pp. 85-89). — This is a brief summary of recent studies on the 

 chemistry of wood. A list of 110 literature references is included. 



The ijroxiniate composition of Korean hemp and ramie, Y. Uyeda (Jour. 

 Indus, and Enyin. Chem., 12 (1920), No. 6, pp. 57.i-576).—This paper, from the 

 California Experiment Station, is the first of a series of reports on Korean bast 

 fibei-s from the standpoint of textile chemical research. The methods proposed 

 by Dore (E. S. R., 41, p. 14) for the proximate analysis of wood were applied 

 with slight modifications to the analysis of samples of Korean hemp (Cannabis 

 sativa) and of ramie (Bcjehmeria nivea), both of which were retted and scutched. 

 The results obtained are given in the following table: 



Proximate analysis of Korean hemp and ramie. 



Three new sources of fuel alcohol (Automotive Indus., Auto., 4^ (1920), 

 No. 2, pp. 80-83; also in Sci. Amer. Mo., 1 (1920), No. 6, pp. 53 1-53 /f).— This 

 article consists principally of a translation of technical, appendixes to a 

 German war-time law concerning alcohol manufacture. These appendixes de- 

 scribe a process for manufacturing alcohol based on the use of molasses, a 

 process utilizing the sulphite liquor of plants for the purification of wood pulp, 

 a process consisting in saccharifying wood and fermenting the sugar thus pro- 



