818 EXPERIMENT STATION RECORD. [Vol. 37 



of extracting the water-soluble potash from 7 tons of dust being accomplished in 

 less than 50 minutes. Under filter-press treatment a cake is formed and removed, 

 and the remaining solution evaporated and the salt collected for grinding and 

 sacking. Six lbs. of potassium sulphate is now being recovered at the plant 

 for every barrel of clinker burned, which at present prices is worth from 40 to 

 50 cts. per barrel of cement produced. 



The possibilities of developing an American potash industry, R. K. Mkade 

 {Metallurg. and Chem. Engin., 17 (,1911), No. 2, pp. 78-87; abs. in Sci. Abs., Sect. 

 B— Elect. Engin., 20 (1917), No. 10, p. 567).— This is a rather comprehensive 

 survey of the present potash situation in the United States and a discussion of 

 future possibilities along this line. 



The author believes " that the largest future source of cheap potash available 

 In this country is in the iron industry and the cement industry. Germany is 

 reported to have $150 invested in her potash mines and equipment for every ton 

 of potash produced annually. On this basis ?37.000.tX>0 would be needed to pro- 

 duce the 250,000 tons of potash imported into this county. . . . The expenditure 

 of this amount of money in this country in these two industries alone would 

 result in the recovery of potash now lost amounting to nearly 2tX).000 tons. The 

 balance could easily be obtained from the evaporation of lakes and brines, from 

 beet-sugar waste, and from some of the proces.ses now proposed for the manu- 

 facture of potash direct from feldspar or glauconite." 



A key to the soil for better crops is soluble ground limestone (hulinnnpolis, 

 hid.: Indinna .\gr. Ground Limestone Assoc. [1917], pp. io).— This pamphlet 

 briefly describes the use of ground limestone on soils. 



Lime report, 1916, J. \V. Kellogg et al. (/'e««. Dept. .{gr. Bui. 294 (1917), 

 pp 55). — This is the report of the oflicial inspection and analysis of agricul- 

 tural lime in Pennsylvania for 1916. 



Fertilizer report, August 1 to December 31, 1916, J. W. Kellogg (Penn. 

 Dept. Agr. Bui. 2SS (1917), pp. 7/).— This is a report of the official inspection 

 and analysis of fertilizers in Pennsylvania for the period named. 



AGRICULTURAL BOTANY. 



The botany of crop plants, W. W. UonniNS {Philadi Iphia : I\ Blakision's Son 

 rf Co., 1917. pp. XIX+6S1, figs. 262). — This book, intended for agricultural and 

 nonagricultural students, is designed to give a knowledge of the common or- 

 chard, field, and garden crops, more than 100 being treated. After an introduc- 

 tory part in which the fimdamentals of plant structure, function, activity, and 

 classification are dealt with, the different crops are taken up in the order of 

 their families, the liabits of the plants, their distinctive characteristics, distribu- 

 tion, production, and uses being described. Keys are given of the principal 

 economic types that will aid the student in recognizing and identifying forms 

 with which he is unfamiliar. 



Important range plants: Their life history and forage value, A. W. Samp- 

 son {U. S. Dept. Apr. linl. 5.',5 (1917), pp. 63. pis. 56).— The results are given 

 of a study of the habits, requirements, and life history of more than 50 species 

 of forage plants in the Wallowa National Forest in northeastern Oregon. Pre- 

 liminary information regarding the palatability of the plants was obtaineil by 

 observing sheep while feeding, and afterwards the relative value of the indi- 

 vidual species was determined by studying their abundance, distribution, time 

 of flower-stalk proiluction, aggressiveness, reproduction (both vegetative and by 

 seed), their palatability and nutritiousness at various times during tlie grazing 

 season, and their ability to withstand trampling. 



