RECENT WORK IN AGRICULTURAL SCIENCE. 



CHEMISTRY. 



The chemical nature of diastase, T. B. Osborne and G. F. (Camp- 

 bell {Connecticut !Staie Sta. lipt. 18'J5,2W- 233-238). — A contiunatioii of 

 studies reported in the Annual Report of the Station for 1894 (E. S. R., 

 7, p. 182). "As yet no preparations of diastase liave been realized more 

 active than those there described. The results given in the former 

 paper, however, have been confirmed, and details of the process for 

 obtaining highly active diastase have been determined more exactly." 



After studying more thoroughly the conditions under which diastase 

 may be separated from the other malt proteids, considerable quantities 

 of diastase were prepared from a malt extract rich in diastase obtained 

 from the Maltine Manufacturing Company. All efforts to get a dias- 

 tase of greater power tlian 300 by fractional precipitation with alcohol 

 failed. Several hundred tests were made of tlie influence of various 

 conditions on the diastatic action, but "in the majority of instances no 

 such uniform results were attainable as wcmld lead to safe conclusions 

 in regard to the circumstances that insure a high degree of diastatic 

 activity." 



"From our experionce in testing these preparations it would seem that the purer 

 the diastase is made, the more sensitive it is to external conditions, and that the 

 method of testing the purity of the ferment by its maltose-producing power thus 

 becomes of uncertain value and perhaps fails to furnish a safe criterion of the purity 

 of the enzym. That the proteid is not the only factor involved in the amylolytic 

 action of diastase is indicated by (he great influence on its activity that often accom- 

 panies the addition of various substances to its solution. In view of these facts, it 

 is not at all improbable that in thus attempting to purify diastase we remove some 

 substance that favors, or is essential to its action, and that we may have in hand 

 what may be properly termed the enzym itself, which is feeble in its operation 

 through the absence or deficiency of some accessory substance. Thus the addition 

 of sodium chlorid in many cases increases the diastatic action several fold. That 

 the albumin is an essential factor in diastatic action could not be positively proved, 

 but the results of further experience have tended to strengthen this belief. Of all 

 the prei>arations that we have made, none from which albumin was absent showed 

 amylolytic power, and those containing the most albumin were the most active. It 

 was always possible to roughly judge of the diastatic jiower of a preparation by 

 heating a portion of its solution to 6.5° C. and observing the amount of coagulum 

 formed. 



"The fact that active diastase was obtained only from solutions whose alcohol 

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