July 28, 1922] 



SCIENCE 



115 



to diabetic patients: Max Kahn. It is prohib- 

 itive to feed diabetic patients who have a very 

 low carbohydrate tolerance even a moderate 

 amount of natural fat because of the danger of 

 inducting a severe ketosis which may prove fatal. 

 It was found that synthetic non-ketogenic odd- 

 earbon fats could be fed in large quantities to 

 such persons without inducing any acidosis, and 

 that the nutrition of such individuals was im- 

 proved. A study is now being made of the inter- 

 mediate metabolism of these fats and their effect 

 on all types of diabetic and normal individuals. 



A new source of santonin : Arno Viehoever 

 and EUTH G. Capen. As a result of a survey of 

 American plants it is evident that santonin can 

 be obtained from Artemisia mexicana and Arte- 

 misia neo-mexicana, which grow wild in Mexico, 

 New Mexico and neighboring states. The survey 

 thus far made comprises 17 species and plant 

 material obtained from 30 different sources. The 

 santonin isolated was identified by the form and 

 refractive indexes of the crystals, the melting 

 point, furfural reaction and the formation of 

 santonin periodide. Though no quantitative data 

 are as yet on hand, the manufacture of santonin, 

 now quoted at $150 per pound, from domestic 

 s'nirees appears a distinct possibility. (Contri- 

 bution from the Pharmacognosy Laboratory, 

 Bureau of Chemistry, Department of Agricul- 

 ture). 



A new method for the colorimetrio determina- 

 tion of Peroxidase: Victor E. Levine. The 

 leuco base of malachite green is used as the re- 

 agent. In the presence of peroxidase this com- 

 pound turns emerald green on the addition of a 

 small quantity of hydrogen peroxide. Proteins 

 of the enzyme extract are coagulated by chloro- 

 form, which also dissolves out the green dye. On 

 centrifuging the mixture separates into a green 

 chloroform layer on the bottom and a colorless 

 layer on top. Between these two layers is a zone 

 of coagulated protein. The chloroform solution 

 is separated from the other layer and is made up 

 to volume. The removal of the proteins renders 

 the extract clear for colorinietric examination. 

 The standard is a solution of malachite green in 

 chloroform. It must be made up fresh as it has 

 a tendency to deteriorate on standing. 



A simple method for differentiating boiled or 

 pasteurised milk from unboiled or unpasteurized 

 milk; Selenium compounds as biochemical re- 

 agents: Victor. E. Levine. 



The catalytic properties of the metals occurring 

 in respiratory pigments: Victor E. Levine and 

 Arthur C. Antony. 



DIVISION OF SUGAR CHEMISTRY 



S. J. Osborn, chairman 

 Frederick Bates, secretary 



The moisture absorptive power of different 

 sugars and carbohydrates : C. A. Browne. Com- 

 parisons were made of the water absorptive 

 power of anhydrous dextrose, levulose, rhamnose, 

 sucrose, maltose, lactose, raffinose, starch, cellu- 

 lose, mannite, invert sugar, honey, molasses, malt 

 syrup, commercial glucose and agar under dif- 

 ferent conditions of atmospheric humidity. The 

 substances of greatest absorptive power at end 

 of one hour exposure (at 20° C, 60 per cent. rel. 

 humidity) were starch (1.04 per cent), cellulose 

 (0.89 per cent.), agar (0.88 per cent.), and of 

 least absorptive power dextrose (0.07 per cent.), 

 mannite (0.06 per cent.), sucrose (0.04 per cent.). 

 At the end of nine days ' exposure the substances 

 of greatest absorptive power were agar (20.34 per 

 cent.), starch (12.98 per cent.), raffinose (12.90 

 per cent.), and of least absorptive power dextrose 

 (0.07 per cent.), mannite (0.05 per cent.), 

 sucrose (0.03 per cent). At the end of 25 days' 

 exposure at 20° C. and 100 per cent, humidity the 

 substances of highest absorptive power were 

 invert sugar (76.58 per cent.), honey (74.10 per 

 cent.), levulose (73.39 per cent.), and of lowest 

 absorptive power cellulose (12.57 per cent.), 

 lactose (1.38 per cent.), mannite (0.42 per cent.). 

 The presence of levulose increases water absorp- 

 tive power, but the latter is not proportional to 

 the levulose content. The absorptive power of 

 the substances was lowest in February and high- 

 est in July and August. The natural fluctuation 

 noted from some substances were: levulose, 

 11.19-36.31; invert sugar, 11.81-34.73; agar, 

 21.00-30.74; starch, 12.29-18.41; eeUulose, 5.06- 

 10.89; maltose, 5.46-9.37; manndte, 0.22-0.52. The 

 general tendency of sugars is to absorb moisture 

 up to the amount necessary to form a stable 

 hydrate form. 



Sugar purity determinations: W. D. Horne. 

 Great numbers of sugar purity determinations 

 having to be made daily for chemical control of 

 sugar factories and refineries, a very rapid and 

 accurate method has been evolved, by means of 

 special appliances. A Brix spindle containing a 

 complete temperature correction scale gives a 

 correct Brix for any density and temperature. 

 Defecation with "dry lead" is practically instan- 

 taneous and more accurate than by the use of 

 lead solution. From the Brix and the polariza- 

 tion thus obtained, one finds the purity on a table 

 of purities printed on a long paper mounted on 

 mova;ble rolls easily exposing the desired portion. 



