AGRICULTURAL CHEMISTRY AGROTECHNY. 205 



no oxidase test with phthalin developed a deep red color on the addition of a 

 drop of phenolphthalein, lends to the conclusion that the enzym has been used 

 up in the curing process and is practic;illy absent in the cured siimple. The 

 above is in harmonj- with Loew's work [E. S. R., 11. p. 727; 12. p. 545], since 

 in several samples he obtained no test and in others only a slight test for 

 oxidase in the different varieties of cured tobacco which he used in his work." 



During the fermentation process losses occur which often amount to 15 per 

 cent, and about one-fourth of this is considered dry matter. Among the gases 

 forme<l during the fermentation period ammonia is easily detected in the 

 fermentation room. During the fermentation process practically all the starch 

 is hydrolyzed by diastase and the re.sulting sugar is changed into other sub- 

 .stances by oxidation. The fact that good invertase reactions were noted led 

 the authors to believe that possibly sucrose may be present and that this may 

 be stored in the root and afterward translocated to the leaf and other parts of 

 the plant during photosynthesis and growth. The protein content of the 

 leaf decreases during the maturation period and this is due to proteolytic 

 enzyms. Amino compounds are formed and the nitrate and nicotin contents 

 of the leaf are decreased. A decrease in nitrates is brought about by the 

 reductases which are present. 



" Some enzyms perhaps have a role in the decrease of the resin and gums in 

 fermentation. If this is true, such enzyms are very necessary, for it is believed 

 that the aroma of a tobacco is partly due to the products formed from the 

 gums and resins after these are broken down. The aroma may partly be due to 

 the breaking up of the glucosids in the tobacco by the glucosid ferment forming 

 an aromatic substance. It is of interest to note, in this connection, that some 

 experiments have been made in this work using emulsin to prove the presence 

 of a glucosid in the green and cured leaf . . . The results proved that there was 

 a small amount of glucosid present. Furthermore, there is no doubt but that 

 positive tests were obtained for a glucosid-splitting ferment. 



" If there is a large amount of fat or protein present in the leaf these will 

 create products during combustion which will injure the flavor and aroma of 

 the tobacco. It is due to lipase and the pi-oteolytic enzyms that these ob- 

 jectionable compounds are largely done away with, provided, however, that they 

 have favorable conditions under which to accomplish their work. 



" During the process of smoking an ethereal oil is formed from certain 

 products of the sweat and from this may be due a portion of the flavor. Citric, 

 malic, and oxalic acids are present in the cured leaf, although in smaller 

 quantities than in the green leaf. Part of the citric and malic acids are per- 

 haps transformed in the fermentation to acetic and butyric acids. Thus we see 

 that there are many highly complex chemical changes taking place in the 

 plant during its growth and these continue in the curing and fermentation 

 periods. That the enzyms play a very important part in these changes can not 

 be denied." 



Micro-org'anisms in commercial lim.e-sulphur, C. A. Peters and A. W. 

 Bbooks {Jour. Indus, and/ Engin. Chem., 5 (1913), No>. 12, pp. 1013, 1014). — 

 Manufacturers of commercial lime-sulphur wash have been troubled for some 

 time by the occasional thickening of their product. The consistency of the 

 spoiled product resembled thin catsup and the precipitate consisted almost en- 

 tirely of sulphur. When examined under the microscope, the mixture showed 

 long threads which were identified as vegetable parasites closely allied to the 

 group Beggiatoa. The use of secondhand wooden barrels is supposed to be the 

 source of the contamination. 



Comparison of the Kjeldahl-Gunning-Arnold method with the ofl[icial 

 Kjeldahl and official Gunning methods of determining nitrogen, T. C 



