FERTILIZERS. 935 



potash and magnesium, marl, garbage fertilizer, mussels, screenings, 

 wool combings, wood ashes, granulated tobacco and sulphur, and 

 tobacco stems. 

 A study of the results reported will show that — 



"while varying considerably in price, nitrate of soda, sulphate of ammonia, and 

 the potash salts are quite uniform in their composition, and comparatively safe to 

 purchase without special chemical examination, although, of course, they should be 

 accompanied hy a guarantee. The organic materials, such as dried blood, dried and 

 ground lish, tankage and ground bone, are always more or less variable, and are best 

 purchased w itli special reference to a guarantee. In a majority of these cases this 

 has been done and the amounts of plant food guaranteed have been delivered to the 

 consumer. The samples of South Carolina rock superphosphate or acid phosphate 

 contain available phosphoric acid in amounts varying from 12.05 per cent to 16.73 

 per cent, without any decided relation between content and price. To avoid this 

 uncertainty a system of purchase, in which only the amounts actually delivered are 

 paid lor. is recommended." 



The results show an improvement in 1897 over previous years in the 

 matter of conforming to guarantees. Eighty per cent of the brands 

 examined contained as much total plant food as guaranteed, 68 per 

 cent reaching or exceeding their guarantees in all particulars, and 40 

 per cent of the remainder having their deficiencies counterbalanced by 

 aji excess in other respects. 



The average composition, estimated value, and selling price of all 

 brands of complete fertilizers examined during the year | E. S. R., 8, 

 p. 0G6) are as follows: Total nitrogen, 2.54 per cent; total phosphoric 

 acid, 10.0.3 per cent; available phosphoric acid, 8.01 per cent; insoluble 

 phosphoric acid, 2.01 per cent; potash, 5.01 per cent; station valuation, 

 $21.58; selling price, $29.28; actual difference, $7.70; percentage dif- 

 ference, 35.7. 



Analyses of 7 samples of home-mixed fertilizers and 9 samples of 

 fertilizers mixed by regular manufacturers specially for their patrons 

 are reported. 



" [The results show] that the mixtures were, on the whole, of the composition 

 intended, with the advantage on the side of the manufacturers' mixtures. Many of 

 the guarantees, however, are based upon an estimated analysis of the raw materials. 

 The home mixtures, on the average, cost $4.38 less, and the manufacturers' mixtures 

 $0.38 less than their valuation, a difference of $4, which represents the expenses of 

 mixing, rebagging, etc. In either case there is a decided saving over buying the 

 average fertilizer in the average way, since the selling price of the average complete 

 fertilizer is $7.70 more than its valuation." 



Further observations on the growth of various plants upon 

 an acid upland soil, limed and unlimed, H. J. Wheeler (Rhode 

 Island tita. Rpt. lsfx;, pp. 242-272, ph. s). — An account is given of a 

 continuation daring 189G of experiments commenced in 1893 (E. S. K., 

 8, p. 580). The system of fertilizing has been fully described in previ- 

 ous reports, the same method of fertilizing being used in 1890 as in 

 previous years. ~No lime has been applied since 1894. The plants 

 experimented with in 1S90 included grasses (11 species), blue lupines. 



