AGRICULTURAL CHEMISTRY — AGROTECHNY. 205 



sugars. Succinic acid was found to be present in tlie fermented silage. Al- 

 though acetic acid was produced in the silage the author was at a loss to ex- 

 plain why this acid is produced from the alcohol when an abundance of oxygeu 

 was not present. 



Observations of the temperature of silage for a period of 5 years showed the 

 highest temperature at the surface to be 126°. The highest interior temperature, 

 taken 5 ft. from the bottom and from 1 to 2J ft. from the edge, was 86°. "The 

 liighest temi^eratures [were] 6 in. from the surface. More than 3 ft. from the 

 surface no temperature above 82.40 has been observed during the 5 years of 

 observations on silage fermentations of all silos examined. High temperatures 

 mean silage destruction when they are abovt' 100°, and not silage formation. 

 The best temperature for silage fermentation is from 75 to 85° F. because 

 when these temperatures are found in a silo the best silage is found. At this 

 temperature the acid is produced most rapidly and stops the growth of unde- 

 sirable bacteria much sooner than at 65 to 70°. At a temperature below 65° 

 during the fermentation stage a poor quality of silage is produceil." The 

 course of the bacterial growth and temperature curves of the silage were 

 nearly i)arallel. 



The number of acid-producing bacteria, of which the author makes 3 divisions, 

 according to their fermentability, varied with the different years. A cane- 

 sugar medium was found to be better than a lactose medium for differentiating 

 acid from nonacid-producing bacteria. The methods of sampling silage and 

 plating for bacterial counts are given. 



As a conclusion the author points out the following: "Any farm product can 

 be siloed providing there is sufficient sugar in the mixture to be fermented into 

 acid to preserve it. The following mixtures silo successfully and make a very 

 desirable and nearly balanced ration : Alfalfa and rye, clover and timothy or 

 wheat or oats, oats and p(as, and corn and cowpeas or soy beans. A round 

 wooden stave silo, taking all things into consideration, has proven most satis- 

 faclory." A bibliography is appended. 



Agricultural chemistry, R. Otto {GrundzUge der Agrikulturchemie. Berlin, 

 I'Jll, 2. cd. rev., pp. Till +302, figs. 43). — A second edition, revised and enlarged 

 (E. S. R., 10, p. 715). 



Chemical-technical methods of analysis, edited by G. Lunge and E. Bebl 

 {Clicmisch-tcchnische TJntersuchungsmethodcn. Berlin, 1911, 6. cd., rev. and 

 cnh, vols. 3, pp. XXI +1023, figs. 150; 4, PP- XIX+1061, pis. J,, figs. 56).— These 

 volumes deal with general and special methods for analyzing fertilizers, feeding 

 stuffs, gases, the products of gas manufacture, mineral oils, lubricating ma- 

 terials, fats and waxes, resins, balsams and gum resins, rubber, essential oils, 

 the materials and products of cane and beet-sugar manufacture, starch, dextrin, 

 alcohol, wine, vinegar, beer, paper, leather, citric acid, coal-tar dyes, and textile 

 fibers. 



Theory and practice of volumetric analysis, A. Classen (Theorie und Praxis 

 dcr Massanalysc. Lcipsic, 1912, pp. IX +172, figs. 46). — This work, chiefly based 

 upon the results obtained in the inorganic and electi'ochemical laboratory of 

 the technical high school at Achen, deals with indicators, measuring apparatus, 

 titrametric systems, methods for saturation analysis, acidimetric methods, 

 oxidation and reduction methods, iodometry, and analysis by pre<Mpitation. 



Note on the neutral permanganate method for the availability of org'anic 

 nitrogen, J. P. Street (Abs. in Science, n. ser., 35 {1912), No. 898. p. .'/27'). — 

 Adding 1 gm. of sodium carbonate to the neutral permanganate solution, just 

 before adding the material to be examined, overcomes much of the loss in 

 availability which occurs when high-grade ammoniates are mixed with large 

 amounts of acid phosphate. 



