■216 



SCIENCE 



[X. S. Vol. XXVIII. Xo. 711 



can be readily accounted for; and that among 

 the '■ other causes " from which the death 

 jates are diminished puhnormry tuherculosis, 

 pneumonia and infant moiiality are prom- 

 inent. 



Finally, we have raised the qiiestions. To 

 what is this remarkable result of the substi- 

 tution of pure for polluted water due' Is 

 the marked decline in the total death-rate 

 attributable simply to cessation of infection; 

 or is it due to some enhancement of vital 

 resistance; or is it due to the cooperation of 

 these factoids? In other words, must pulmon- 

 ary tuberculosis, pneumonia, infant mortality, 

 ■etc, be added to the list of water-borne dis- 

 eases, or does the use of impiire water depress 

 the vital resistance of the human oi^nisni? 



The complete paper, containing a discussion 

 of these and similar questions, numerous sta- 

 tistical tables, diagrams, etc., will be pub- 

 lished in the near future. 



W. T. Sedgwice 

 Scott iticXcTT 



BlOLOGICAI. DEPAETME>T, 



AIassachusetts IxsTirrTE or Techxologt 



THE TBIRTT-EIGETE OEYERAL ilEETISG 



OF THE AMESWAy CEEMICAL 



SOCIETY— 11. 



BIOLOGICAL .\Xr) SA>-n'AKT CHEMISTKT 



Thomas B. Osborxe, Chairman 

 The Effect of Pastcuri.::ation upon the DcreJop- 



ment of Ammonia in ililk: W. G. Whitmax 



and H. C. Shermax. 



The purpose of this investigation was to follow 

 by accurate quantitati\-e determination the de- 

 velopment of ammonia in raw and pasteurized 

 milk as a possible measure of protein decomposi- 

 tion. The ammonia content of raw milk kept at 

 15° to 20' C. tisnally increased rather rapidly 

 for two days, more slowly during the third and 

 fourth days, and then decreased somewhat for a 

 few days following, increasing again later if the 

 observations were sufficiently prolonged. A simi- 

 lar slight decrease of ammonia toward the end of 

 the first week was sometimes, but not ustially, 

 observed in milk pasteurized at 65°; never in 

 milk pasteurized at S5°, which always showed a 

 continuotis increase in ammonia content. In 

 milk obtained tmder ordinary market conditions 

 in Xew York City and thereafter kept at 15-20°, 

 pasteurization was usually less efficient in check- 



ing the development of ammonia than in checking 

 the prodiiotion of acid, and this was especially 

 true of the milk pasteurized at the higher 

 temperature lS5°) which often developed a rela- 

 tively large amount of ammonia before becom- 

 ing sour. 



Chemical Evidatce of Peptonization in Eaic and 

 Fasten ri:cd Mill-: Eachel H. Colwell and H. 

 C. Shekman. 



An attempt was made to judge roughly of the 

 extent of peptonization from the intensity of the 

 biuret reaction after the removal of coagulable 

 proteins and proteoses. The results indicate that 

 pasteurization at 60° for twenty minutes re- 

 strained peptonization to about the same extent 

 that it restrained sotiring, and had no marked 

 influence tipon the development of oflensive odors. 

 Pasteurization at higher temperatures (75° and 

 90°) delayed souring to a mtioh greater extent, 

 had less restraining effect upon peptonization and 

 resulted in the subsequent development of much 

 more offensive odors. 



Incesticiations of Wheat Oil: Joseth S. Chambee- 



LAix and Geo. L. BmwEix. 



The authors determined the physical properties, 

 the iodine absorption, saponification value and re- 

 fractive index of the crude fats extracted by ether 

 from wheat germ and from wheat flour. The 

 crude fats were then pnirified by treatment with 

 acetone. The soluble portions consisting in each 

 case of pure liquid oil were studied in the same 

 way. The results show that the ptirified oils ob- 

 tained from wheat germ and wheat flour are 

 much more alike than the crude fats. They think 

 it possible that the tisual statement, that these 

 two oils are distinctly difl'erent, may not be true 

 and expect to study the question further. 

 FJant Food removed f>-om Growing Plants hii 



Fain or Deir: J. A. Le Clekc and J. F. 



Breazeale. 



Wheat, barley and other plants were grown in 

 pots in a greenhouse and not subjected to weather- 

 ing conditions. It was demonstrated that the 

 gradual decrease in the total salt content of these 

 crops from the milk stage until final han-est is 

 not due to a physiological process, as was formerly 

 supposed by many investigators, but to a purely 

 mechanical one. The salts do not i-ecede from the 

 plants to the soil through the stems, but are 

 dissolved and leached out V>y rain or dew. 



Analytical data were also cited to show that the 

 same pi-ooess takes place in potato, rice and oat 

 plants and also in tie leaves of trees. 



