682 EXPERIMENT STATION RECORD. 



the largest amount of uncombined lime. The determination of this 

 constituent in slags is therefore of the greatest importance. 



The geology of nitrate formation from the standpoint of bacteriological 

 chemistry, A. Plagemanx {Geoloyischer iiher Salpeterhildung rom Standpunkt dcr 

 Giihrungscliemie. Uamhurg: G. TV.Seitz). — This is a brochure discussing from per- 

 sonal observatious the formation of the nitrate deposits of western South America. 



The formation of phosphate deposits, A. Carxot (Echo des Mines, 3.2 (1896), 

 p. 975; ahs. hi Chem. 7Mj., 21 {1S9G), Xo. 3, nepert., p. 6). 



Theory of the sedimentary phosphorites, S. Meuniek {Ann. Jijron., 23 (1897), 



JS'o. l,2'>P-5-:'7). 



Experiments vsrith peat and excrement mixture and v^ith barnyard manure, 

 TaxcPvE (Landiv. Wochenhl. Schles. HoUl., 47 (1S97), No. 5,])p. 01-94). 



Means of preventing the loss of nitrogen in manure (Prog. Agr. et V\t., 21 (1897), 

 Xo.4,pp.S9,D0). 



Crops for green manuring, E. W. Hilgard (California Sia. Ept. lS95,j)p. llS-123, 

 pis. 4). — The objects of green manuring are explained and the adai)tability of dif- 

 ferent classes of plants to this purpose is discussed. Plates show the root systems 

 of blue grass, scjuare-pod pea (Tetragonolohus purpureuH), snail clover, and black 

 acacia, the last 3 illustrating especially the root tubercles of leguminous plants. 



The relative value of green and dry vegetation for plowing in, and of green 

 manuring and stable manure is also discussed. 



Tests of chemical fertilizers in 1896, C. Dussehe (Chron. Agr. Cant. J'aud,10 

 (1897), Xo. 3, pp. 69-73). 



Analyses of fertilizers, gypsum, etc., E. W. Hilgakd (California Sta. Bpt. 1895, 

 pp. 135-139). — Partial or complete analyses are re^jorted of 10 samjiles of fertilizing 

 materials, including mixed fertilizers, sulphate of potash, bird guano, ostrich manure, 

 lime refuse, and 16 samples of gypsum. 



Analyses of commercial fertilizers, H. J. Wheeler, B. L. Hartwell, and C. L. 

 Sargent (lihode Island Sta. Bui. 39, pp. 61-68). — A schedule of trade values of ferti- 

 lizing materials and notes on valuation are giveu^ with tabulated analyses and 

 valuations of 41 sam])les of fertilizers. 



Analyses of commercial fertilizers, T. J. Edge and W. Frear (Pennsylvania 

 Dept. Agr. Bui. 10, pp. 39). — This includes the text of the State fertilizer law, notes 

 on valuation, and tabulated analyses and valuations of 588 samples of fertilizers 

 examined during the year ending December 31, 1896. 



FIELD CROPS. 



Conditions affecting the starch content of potatoes, E. S. Goff 



{Wisconsin Sta. Rpt. 1895, pp. 317-331). — In this article the author 

 considers the variation in starch content in difierent varieties, in dif- 

 ferent seasons, and between different specimens of the same variety; 

 the inHueuce on the starch content of heredity, the depth at which the 

 tubers grow in the soil, distance in planting, climate, greening, seabbi- 

 ness, and size; also the distribution of starch within the potato tuber, 

 and the relation of starch content to cooking quality. The specific 

 gravity of the tubers was used as a measure of their starch content. 

 Tabulated data are given under the different divisions of the subject. 

 The author concludes as follows : 



" (1) Different varieties of the potato, grown under the same cultural conditions, 

 may vary in their food value to the extent of one-half or more. 



"(2) The starch content of the same variety and on the same soil may vary consid- 

 erably in different seasons. 



