676 



SCIENCE 



[N. S. Vol. XXXVII. No. 957 



discarded. By the latter practise there is also lost 

 from a quarter to a third of the soluble solids of 

 the fruit. 



Edwakd Bartow: The Effect of Chicago's Sewage 

 on the Illinois Biver. 



Tests made during a dry season in July show 

 a very low content of dissolved oxygen in the 

 river as far down as the Marseilles dam. Below 

 the dam there is a gradual rise as far as Peoria, 

 below which there is a slight drop, followed by a 

 rise and higher values throughout the remainder 

 of the river. During high water and in colder 

 weather more oxygen is present in the upper part 

 of the river, but there is evidence that the sewage 

 is carried farther down the stream. A study of 

 the fish life of the river by Professor 8. A. Forbes 

 shows no fish present in the river above the Mar- 

 seilles dam. There is an increase in. the number 

 of fish found in the lower part of the river and 

 the amount of plankton is very much greater than 

 before the opening of the drainage canal. 

 A. Hugh Bryan: The Polarisation of Light- 

 colored Sugar Solutions. 



In polarizing light-colored sugar solutions, such 

 as syrups, honeys, extracts, etc., with saooharim- 

 eters, using white light, it is often hard to neu- 

 tralize the field, one side possessing a bluish or 

 greenish tinge and the other a white or reddish 

 one. This results from differences in rotation dis- 

 persion of the sugar solution and quartz wedges. 

 In order to reduce this to a minimum, the white 

 light used as a source of supply for the polari- 

 scope should be filtered through a neutral solution 

 of bichromate of potash. This removes the blue 

 and violet rays which are the main disturbing ones. 

 For solutions of sucrose, a layer IJ cm. thick of 

 a 6 per cent, solution or 3 cm. layer of a 3 per 

 cent, solution has been found sufficient, while for 

 commercial glucose the percentage composition 

 should be double for the same layer of solution, 

 that is, 12 per cent, for a IJ cm. cell or 6 per cent, 

 in a 3 em. cell. Dark-colored sugar solutions nat- 

 urally tend to filter the light. Hence, there is 

 little trouble experienced when polarizing them 

 without the light filter cell, but many sugar chem- 

 ists use the cell in case of all polarizations. 

 Sleeter Bull and A. D. Emmett: The Frotein 

 and Energy Requirements of Fattening Lambs 

 as Determined iy a Study of American Feeding 

 Experiments. 



In this compilation of the American literature 

 upon the protein and energy requirements for 

 fattening lambs, 49 experiments from 16 different 



agricultural experiment stations were reviewed. 

 The experiments embraced 259 lots of 5,005 lambs. 

 The data were classified into four groups, lambs 

 weighing 50-70 pounds, 70-90 pounds, 90-110 

 pounds and 110-150 pounds. The average daily 

 consumption of digestible protein in pounds, the 

 average net energy in therms, and the average 

 daily gains were reported and summarized for each 

 group. 



John G. Diggs: Analyses showing the Composition 

 of the Different Grades of Commercial Pack 

 Peas. 



This paper gives a complete analysis of the 

 various grades of canned peas put out by a single 

 packing concern. It was thought that in one 

 plant where uniform methods were used in grading, 

 sizing and packing a closer distinction might exist 

 between the composition of the different brands or 

 grades. The basis for determining the three 

 brands was the gravity of the first pea. The 

 average of analyses of grades of each brand show: 

 the younger immature peas contain eighteen per 

 cent, more water than the oldest ones, the crude 

 fiber decreases from 10.25 per cent, to 7.15 per 

 cent, (water -free basis) as the pea matures, starch 

 increases from 41 per cent, to 53 per cent, with 

 maturity, sugar decreases as the pea grows older. 

 John G. Diggs: Some Abnormal Factors of So- 

 called Farmers' Cider Vinegar. 

 This paper gives the analysis of eighteen sam- 

 ples of supposed cider vinegar produced by cask 

 fermentation. In many of the samples fermenta- 

 tion was found to have been arrested before com- 

 pletion, these samples containing high percentages 

 of sugar. The maximum factors in grams per 

 100 c.c. were: acid, 10.25; total solids, 9.64; sugar, 

 5.97; non sugars, 5.06; and glycerine, .51. Some 

 of the samples were watered and to some sugar 

 and acetic acid had been added. The difficulty of 

 manufacture of vinegar by this process without at 

 least some training is shown. 

 J. T. Donald: Methods for the Accurate Deter- 

 mination of Saltpeter. 

 J. O. Halverson: The Modified Babeoch Method 

 for Fat in Sweetened Dairy Products — Ice 

 Cream. 



The need of a rapid volumetric method for ice 

 cream is shown. The Babcock test is not appli- 

 cable to sweetened dairy products on account of 

 the well-known charring action of the acid on the 

 sugar. If the sugar solution could be readily 

 drained off, the ordinary Babcock method could 

 then be used. This is accomplished by centri- 



