COCOA BY-PRODUCTS 35 
Canada Experimental Farms report for 1898 contains an analysis 
showing* the crude fertilizer and feed constituents of a sample of 
the by-product (42) ; and a similar analysis is given by Lindsey 
and Smith of the Massachusetts Agricultural Experiment Station 
(28). Cathcart, of the New Jersey station, investigated the 
solubility and quality of the nitrogen in a factory sample reported 
as cocoa shells (8, p. 45). 
The Canadian analysis showing a content of 12.9 per cent of fat 
and 2.63 per cent of nitrogen indicates that the material contained 
an appreciable quantity of the nibs and was comparable with much 
of the commercial cocoa-shell meal now being used in fertilizers. 
This sample contained 1 per cent of phosphoric acid (P 2 5 ) and 
2.6 per cent of potash (K 2 0). The analysis given by Lindsey and 
Smith, which is the average for two samples, shows their material 
to have been of the same type. The average figures were — nitrogen, 
2.45 per cent, of which about one-third was rated available; 
phosphoric acid. 0.7 per cent ; and potash 2.9 per cent. The New 
Jersey sample, on the other hand, contained only 1.92 per cent of 
nitrogen and undoubtedly represents a lower-grade product, as 
even pure cacao shell usually contains more nitrogen than this, and 
the presence of nib or germ would increase the nitrogen content. 
Phosphoric acid was found to the extent of 0.6 per cent. The quality 
of the nitrogen was investigated by the alkaline permanganate 
method, with the following results: Water-soluble nitrogen, 0.35 
per cent; active insoluble nitrogen, 0.34 per cent; inactive insoluble 
nitrogen, by difference, 1.23 per cent (8, p. 4-5)> This checks the 
Massachusetts figure for the " availability " of the nitrogen, as the 
sum of the water-soluble and active nitrogen amounts to about 36 
per cent of the total nitrogen. 
An actual field test of the value of cacao shells as a soil amendment 
is mentioned in a number of books on cocoa and chocolate. The ex- 
periment, which was made at Bournville, where one of the great 
English chocolate factories is located, showed, according to Knapp 
(26), that the availability of the plant food contained in cacao 
shells can be improved by keeping the shells in heaps soaked with 
water and turning over the mass from time to time. Shells that 
were applied directly to the soil, without previous soaking, did 
not decompose readily and yielded their plant food very slowly, 
whereas the shells that had been subjected to wet composting were 
in a decomposed condition when applied and gave good results, 
particularly when used to lighten heavy soil. 
Much more space in the literature of cocoa and chocolate has 
been devoted to discussion of the use of cacao shells in the feeding 
of animals than as fertilizer material. A reason for this is found 
in the fact that a great deal of the published work is of English 
and continental European origin; and Knapp has stated that the 
bulk of the cacao shells produced in England is used in the manu- 
facture of mixed stock feeds (26, 27). Below are given brief 
summaries of the more important references found in the literature 
relating to the feeding of cacao shells. 
Albert (2) reported in a German periodical, in 1899, that the 
shells were a satisfactory auxiliary feedstuff for steers. Dean (11), 
of the Ontario Agricultural College, as a result of feeding experi- 
