946 



SCIENCE 



[N. S. Vol. XLII. No. 1096 



acid and 125 per cent, of water gave an alcohol 

 yield of 8.54 per cent, of the dry weight of the 

 wood or about 25 gallons per dry ton. 

 The Application of the Davis Spot Test in the 

 Preliminary Examination of Creosotes: Homer 

 Clouket. 

 Isoprene from Beta-pinene : A. W. Schoegee and 



Ralph Satre. 

 The Distillation of Douglas Fir at High Tempera- 

 tures: Bailey Teempee. 

 The Manufacture of Ethyl Alcohol from Wood 

 Waste. III. Western Larch as a Baw Ma- 

 terial: F. W. KJEESSMANN. 



The butt log of western larch is usually left in 

 the woods because of the presence of shakes and 

 also because of the weight of the log, which is heav- 

 ier than water and, therefore, sinks, preventing 

 rafting. An investigation of this material showed 

 a sugar yield of 29.7 under the same conditions 

 that would yield about 22 per cent, from white 

 spruce. However, only 37.9 per cent, of the larch 

 sugar was fermentable against from 60 to 65 per 

 cent, of total sugar fermentable from spruce. 

 Analysis of the larch by Mr. A. W. Schorger of 

 this laboratory showed only 42J per cent, of cellu- 

 lose as compared with about 56 per cent, from 

 spruce and also the presence of about 12 per cent. 

 of galactan, which yielded galactose on hydrolysis, 

 which, however, was not fermentable by the yeast 

 used. Calculations show that the proportion of 

 fermentable sugars to cellulose is about the same 

 for larch as for spruce. If a yeast is found which 

 will ferment the galactose as well as the dextrose 

 within the time limits and other limitations, as 

 prescribed by the Bureau of Internal Revenue, this 

 material will afford a very good raw material for 

 the production of ethyl alcohol. 

 The Production of Acetone from PyroUgneous 

 Acid: Maec Daeein. 



DIVISION OP AGRICULTUEAL AND POOD CHEMISTET 



Floyd W. Robinson, Chairman 



Glen ¥. Mason, Secretary 



The Activity of Proteolytic Enzymes in Bread- 



maTcing : Aenold Wahl. 

 The Spontaneous Decomposition of Butter Fat: 



C. A. Browne. 



The analytical constants are given for a num- 

 ber of butter fats exposed to the light and air be- 

 fore and after a period of 15 years. The results 

 show that the fats have undergone an increase in 

 the acid, saponification and volatile acid num- 

 bers and a decrease in the ether and iodine num- 

 bers. The mean molecular weight of the free 



volatile acids was 91.7 and of the combined vola- 

 tile acids 105.4; the average mean molecular 

 weight of the total volatile acids was 99.5, which 

 agrees closely with that for normal butter fat. 

 The total percentage of volatile acids had in- 

 creased from 7.2 per cent, to 8.6 per cent, and the 

 total percentage of insoluble acids had decreased 

 from 87.6 per cent, to 79.7 per cent. The insol- 

 uble acids had an acetyl number of 36.4 corre- 

 sponding to 20 per cent, of hydroxy-stearic acid 

 and an ether number of 8.3 corresponding to 4.2 

 per cent, of stearo-lactone. A proximate analysis 

 of the decomposed butter fat gave 63.50 per cent, 

 neutral fat, 27.15 per cent, free insoluble acids, 

 3.90 per cent, free soluble acids, 5.42 per cent, 

 undetermined. The iodine number of the free in- 

 soluble acids was 11.3 and of the combined in- 

 soluble acids 12.1. Experiments upon the change 

 in weight which butter fats undergo with ago 

 showed that there was a 2 per cent, to 3 per cent, 

 increase in weight in about one year, the period 

 of greatest increase being about the tenth week. 

 Very old butter fats lose in weight, owing to the 

 escape of water, carbon dioxide, volatile acids 

 and aldehyde decomposition products. The theo- 

 ries of the spontaneous decomposition of fats are 

 discussed; the author believes that the observed 

 facts are best explained by supposing an absorp- 

 tion of oxygen molecules from the air at the un- 

 saturated bonds, one atom of active oxygen being 

 liberated for each atom of oxygen absorbed. The 

 disintegration of the glycerides, being propor- 

 tional to the percentage of unsaturated acids, is 

 attributed to the action of the active oxygen. 

 Experiments are cited to prove that such atoms of 

 active oxygen are formed. 



The Analysis of Maple Products. V. Miscellane- 

 ous Observations on Maple Syrup Incidental to 

 a Search for New Methods of detecting Adul- 

 teration: J. E. Snell. 



(1) Silver nitrate added to maple syrup gives 

 a white precipitate which darkens on standing. 

 The precipitation of silver continues during a 

 period of several hours. (2) Mercuric acetate 

 added to maple syrup produces a light yellow 

 precipitate. (3) Alcohol produces a precipitate 

 containing most of the calcium and potassium. 

 (4) A moderately successful attempt was made to 

 combine the advantages of the Winton and Ca- 

 nadian lead subaeetate methods. (5) The Ca- 

 nadian lead precipitates from six syrups showed a 

 lead content of 66.95 to 69.62 per cent. Average 

 68.42. The precipitate from a composite of 542 

 syrups contained 69.41 per cent, of lead, while 



