622 



SCIENCE. 



[N. S. Vol. XXIII. No. 590. 



The Use of Carbon Tetrachloride with the 

 Soxhlet Apparatus: Roscoe H. Shaw. 

 Various chemicals have been advocated 

 and used as extractants in the determina- 

 tion of fat in foods and agricultural prod- 

 ucts. Ether is most extensively used and 

 its use has become official. Carbon bisul- 

 fide, petroleum ether and carbon tetrachlo- 

 ride are also used to some extent. The 

 last named has many advantages over the 

 others. It is cheap, it can be purchased 

 pure and its vapor is non-explosive, non- 

 inflammable and non-poisonous. Ether 

 can not be obtained anhydrous and must 

 be kept over sodium and redistilled just be- 

 fore using. It is expensive and its vapor 

 is explosive. The unpleasant odor and 

 poisonous property of the vapors of car- 

 bon "bisulfide restrict its use. Petroleum 

 ether is a mixture of the lighter oils of pe- 

 troleum and consequently has no definite 

 chemical composition or boiling-point. 



Samples of corn and linseed meal were 

 extracted with both ether and carbon tetra- 

 chloride. The heat for those with ether was 

 supplied by a steam bath and for the carbon 

 tetrachloride direct fiame with an asbestos 

 plate interposed. Soxhlet 's extractors were 

 used in each case. It was found that the 

 tetrachloride made the complete extraction 

 and gave identical results with the ether in 

 about one third of the time required by 

 the latter, and that a previous drying of the 

 samples was unnecessary. Extractions on 

 other grains will be made and reported at 

 the next meeting. 



Some Carboniferous Corals from Ne- 

 braska: E. H. Barbour. 



Forest Planting in Eastern Nebraska: 



Frank G. Miller. 



This paper dealt mainly with that part 

 of the state east of the ninety-ninth meri- 

 dian. It reviewed briefly the history of 

 forest planting in Nebraska, in which it 



was noted that the state has about 300,000 

 acres of planted timber, approximately 

 250,000, or 83 per cent., of which are in the 

 region east of the ninety-ninth meridian. 

 The observation was also made that in the 

 eastern portion of the state the planted 

 area is decreasing. Owing to the rapid ap- 

 preciation in the price of land, together 

 with an increased timber supply, due to the 

 efforts of the early settlers, the activity in 

 forest planting so characteristic of pioneer 

 days has gradually declined, till in the past 

 few years the amount of planting done in 

 most parts of the region under considera- 

 tion has been very small, and this has been 

 more than offset by the large amount of 

 former planting that is being harvested. 

 Tree planting declined very rapidly from 

 about 1894. The outlook for future plant- 

 ing is more hopeful, as there is a distinct 

 revival of interest in forest planting at the 

 present time. In mentioning the purposes 

 for which forest plantings should be made, 

 their protective value was especially em- 

 phasized. The ability of wind-breaks and 

 shelter belts to protect planted fields and 

 orchards from the aridity of the wind and 

 thus increase crop production is not only 

 attested by common observation, but has 

 been demonstrated by experimentation. 

 This is one of the most vital questions con- 

 nected with tree planting on the plains, 

 since the importance of any agency that 

 will retard the velocity of the wind and 

 thus check evaporation becomes at once ap- 

 parent. For commercial purposes, com- 

 mon Cottonwood and willow were recom- 

 mended for fuel. For fence posts, hardy 

 catalpa, honey locust, green ash, Osage 

 orange, European larch and red cedar were 

 named; while for lumber production, com- 

 mon Cottonwood and black walnut are the 

 most available trees. 



Cantor's Transfinite Numbers: E. W. 

 Davis. 



