August 5, 1904.] 



SCIENCE. 



181 



type, which latter group Freer* and Novy 

 have demonstrated to be among the strongest 

 germicides known. The formation of such 

 toxic products would be of immense value to 

 plants in protecting them against infection 

 by micro-organisms, when their tissues are 

 injured. Such protection would be most 

 necessary in the regions of intense growth, 

 and there in fact we find the oxidizing eiiect 

 of the vegetable enzyxaes to be the greatest. 

 The toxic products formed would undoubtedly 

 have an injurious action upon the plant itself, 

 were this not prevented by the reducing en- 

 zymes, which prevent the diffusion of these 

 substances beyond their points of formation 

 and requirement. 



The oxidizing enzjrmes, no doubt, take part 

 in other important physiological processes be- 

 sides that of promoting the formation of toxic 

 products. The importance of the latter -func- 

 tion seems, however, to have been generally 

 overlooked, and I believe it to constitute a 

 phase of enzyme action well worthy of future 

 investigation. 



0. A. Browne, Jr. 



Louisiana Sugar Experiment Station, 

 Audubon Paek, New Orleans, La. 



the endosperm enzyme of phcenix dactylip- 



ERA — PRELIMINARY REPORT. 



The presence of an enzyme in the resting 

 endosperm of the date seed has been demon- 

 strated as follows: After the embryos were 

 excised from a quantity of seeds the endo- 

 sperms were ground to a coarse powder and 

 this powder digested cold for six hours with 

 distilled water. The aqueous extract thus ob- 

 tained was made 40 per cent, alcoholic, after 

 which precipitate No. 1 settled. This precipi- 

 tate was collected over asbestos and washed 

 with alcohol while the filtrate No. 1 was raised 

 to 80 per cent, alcoholic, after which precipi- 

 tate No. 2 settled. This precipitate No. 2 was 

 collected over asbestos and washed with al- 

 cohol. A portion of precipitate No. 1 was 

 digested with 95 per cent, alcohol with con- 

 stant shaking for fifteen minutes. The ex- 

 tract was filtered and evaporated to dryness 



* Freer and Novy, Ainerican Chemical Journal, 

 27, 161-192. 



over steam. A very slight residue remained 

 which was insoluble in water and probably 

 consisted of very fine asbestos which passed 

 through the filter. This residue insoluble in 

 water would not affect Fehling's solution, as 

 was expected. The remainder of precipitate 

 No. 1 was extracted with water and the ex- 

 tract filtered. The filtrate was made 50 per 

 cent, alcoholic and digested ten days at labo- 

 ratory temperatures, after which time it was 

 evaporated to dryness over steam, yielding 

 residue No. 1. This residue was digested for 

 several hours with 95 per cent, alcohol, the 

 extract filtered and evaporated to dryness, 

 yielding residue No. 2, which was found to be 

 very soluble in water and to reduce Fehling's 

 solution. Precipitate No. 1, consisting of 

 carbohydrates insoluble in 40 per cent, alcohol 

 and any proteid either insoluble or carried 

 dovm with the carbohydrates — evidently dur- 

 ing the ten days' digestion in 50 per cent, al- 

 cohol — developed a reducing sugar soluble in 

 95 per cent, alcohol. Precipitate No. 2 was 

 extracted with water and the extract filtered. 

 The filtrate thus obtained was measured 

 equally into four flasks. Into each flask 5 c.c. 

 of soluble starch was titrated. Flasks A and 

 B were immediately made 80 per cent, alco- 

 holic. Flasks C and D remained without al- 

 cohol. All four flasks were digested at 40° 0. 

 for six hours. The solutions were then evap- 

 orated to dryness, yielding residues A^, B^, 0^, 

 Z*,. Each of these residues was then digested 

 for several hours with 95 per cent, alcohol. 

 The extracts were filtered, and after evapora- 

 tion to dryness the residues A„, B,, G^, D, thus 

 obtained were dried for one hour at 110° C, 

 removed to desiccator and weighed with fol- 

 lowing results. 4, = 0.0085 gms., B, = 0.0090 

 gms., C, = 0.0080 gms. and J>, = 0.0085 gms. 

 All of these residues were soluble in water 

 and reduced Fehling's solution with a total of 

 0.0030 gms. of CuO. Whether this reducing 

 sugar developed from the soluble starch or 

 from the carbohydrates present in precipitate 

 No. 2 is unknown. Evidently the activity of 

 the enzyme contained in precipitate No. 2 is 

 not inhibited by 80 per cent, alcohol. 



Raymond H. Pond. 

 Northwestern University. 



