July 27, 1917] 



SCIENCE 



95 



Peaches decomposed rapidly about the spot where 

 an injection of invertase had been made, or in a 

 solution of invertase. SimUar experiments are in 

 progress with apples, in an effort to explain the 

 discrepancy between the decrease in sucrose con- 

 tent of apples during ripening found by Bigelow, 

 Gore and Howard and the absence of invertase 

 from the apples studied by Thatcher. Flesh and 

 epidermis of peaches kept in an atmosphere of O, 

 for two months became golden yellow, but turned 

 brown quickly on exposure to air. The flesh was 

 soft, contained a little alcohol, and had an insipid 

 taste. Quantitative study of the respiration of 

 apples in an atmosphere of oxygen, showed that 

 the rate is higher under this condition than in an 

 atmosphere of air. 



Quantitative determination of carbohydrates in 

 plant tissues: T. W. Muncie and D. T. Englis. 

 If fresh plant tissue is plunged into warm alcohol 

 and after standing two weeks, the alcohol removed 

 by decautation and expression before extraction 

 with hot alcohol, a large percentage of the sugar 

 (96 per cent, in one experiment) is removed and 

 loss of fructose by hot extraction largely avoided. 

 Mercuric nitrate is more satisfactory to use than 

 the acetate and 10 per cent, phosphotungstic acid 

 than the more concentrated solution used by them. 

 Asparagin also is quantitatively removed from so- 

 lution by mercuric nitrate provided the solution is 

 made just alkaline to litmus with sodium hydrox- 

 ide or carbonate after addition of the mercuric 

 salt, then just acid with a few drops of weak acid. 

 No mercuric oxide is precipitated by such a pro- 

 cedure. These reagents, especially the phospho- 

 tungstic acid, invert sucrose so quickly that they 

 are not applicable to the determination of a mix- 

 ture of sucrose, glucose and fructose, excepting 

 when sucrose has been previously determined. This 

 may be done by using basic lead acetate as the 

 clearing agent, by the polarimetric method if the 

 inversion is made with invertase or solution again 

 made neutral after use of acid. When the value 

 for sucrose is knovrn, the original solution par- 

 tially cleared with SOi-free alimaina cream is in- 

 verted with invertase, then nitrogenous impurities 

 removed with mercuric nitrate and phosphotungstic 

 acid and total glucose and fructose determined. 

 Subtraction of value for sucrose leaves the values 

 for glucose and fructose present in the original 

 solution. 



A physical and chemical study of the Tiafir Tcer- 

 nel: George L. Bidwell. Dwarf, black-hulled, 

 white kafir kernels were separated by hand into 

 bran, germ and endosperm. These parts were 



analyzed and compared to corresponding parts of 

 corn and were found to resemble them closely. In 

 the bran a wax-like substance was found. The 

 ether extract of the germ was found to be liquid. 

 The endosperm yielded an ether extract not yet 

 examined. The coloring matter in this sample 

 does not seem to be associated with tannin. The 

 endosperm may be separated into starchy and 

 horny parts, the former having less protein than 

 the latter. 



Oil from the anocado: H. S. Bailey and L. B. 

 BuKNETT. The production of the avocado or alli- 

 gator pear in the United States is increasing so 

 rapidly that there is a possibility of large quanti- 

 ties of this fruit being available as a source of oil. 

 The fruit when fully ripe contains approximately 

 80 per cent, of moisture and the dried material 

 about 50 per cent, of oil. So far no method has 

 been found by which the oil can be extracted from 

 the fruit in a sweet, edible condition, and as the 

 oil when extracted with ether and the solvent re- 

 moved at low temperature in vacuum has a bitter 

 taste, it is very doubtful whether the oil as it ex- 

 ists in the fresh fruit itself is palatable if sepa- 

 rated from the accompanying pulp. By means of 

 the usual hydrogenation process it is compara- 

 tively easy to convert either the expressed oil or 

 that extracted by solvents into a solid, white, 

 tasteless, fat which resembles in its physical prop- 

 erties ordinary hydrogenated cottonseed oil. 



Oil from the Stillingia sehefera: H. S. Bailey 

 and L. B. Burnett. The fruit of the semi-trop- 

 ical tree Stillingia sehefera, which grows in China 

 and has been introduced into some of the southern 

 states of this country, produces two glycerides. 

 The exterior of the seed is covered with a wax-like 

 substance from which is derived the Chinese 

 vegetable taUow of commerce. The interior of the 

 seed contains an oil usually known as stillingia oil. 

 Certain statements in the literature indicate that 

 this oil even in China is not used for food purposes 

 and probably has poisonous properties. The con- 

 stants of these oils have been determined, and ex- 

 periments made by Dr. WiUiam Salant, of the Bu- 

 reau of Chemistry, in feeding rabbits with both 

 the expressed and extracted oils. So far as the 

 results obtained with the small amount of ma- 

 terial available are conclusive, it appears that 

 stillingia oil is not toxic and has practically the 

 same effect as other vegetable oils. 



A noteworthy effect of bromides upon the action 

 of malt amylase: Arthur W. Thomas. The ac- 

 tion of sodium and potassium bromide upon malt 

 amylase was found to be inhibitory when present 



