No. 3 (1921) MANUFACTURE OF FISH OIL AND GUANO 24I 



It will be noticed that 5 tons of this lightly salted fish dried 

 into l/^ tons fertilizer as against ll4 tons of unsalted fish ; this is 

 doubtless due to the hardening of the tissues by the salt so that 

 breakage is minimised and also the loss of weight by putrefac- 

 tion. 



The percentage of nitrogen in this larger quantity of lightly 

 salted material is noteworthy ; other analyses of similar material 

 gave6'34, 6'63 and 7*43 of nitrogen and from 5 to 6'55of phosphoric 

 acid. This confirms the excellence of this very simply prepared 

 manure ; the method however is mainly intended for It'a/i fish, 

 since all the oil in the fish goes into the fertilizer which is bad for 

 the buyer and for the soil; if the fish is at all fat, it pays better 

 to boil and press it as usual. Similar whole lean fish, entirely 

 unsalted but dried artificially in a drier, gave the large percentages 

 of 7"59 nitrogen and 6'88 phosphoric acid showing the high 

 manurial value obtainable by simple drying in artificially heated 

 driers. 



143. The drying experiment was not continued as the building 

 and working of an economical drier was beyond the technical 

 resources of the yard. Probably a masonry drier, either vertical 

 or horizontal, worked not by trolly carriages as in the abortive 

 Tanur drier but by a conveyor, would be suitable; a vertical drier 

 (wrongly called " horizontal ") is roughly described on page 439 of 

 the Imperial Institute Bulletin, Volume XII, No. 3 for July—Septem- 

 ber 19:4. 



144. The price of beach-dried fish varies immensely from year 

 to year, owing especially to the presence or absence of sardine 

 shoals and to the fatness or otherwise of the fish ; but the general 

 level of prices has, since 1906,^ gone up very heavily. At that time 

 Rs. 20 to 22 was commonly obtained by the fisherfolk ; in 1911— 13 

 intermediaries sold the stuff to the great Coastal firms at Rs. 28 to 

 Rs. 33, or at Rs. 45 c.i.f. Colombo, 15 per cent sand being allowed 

 at ihese prices. Owing partly to a rise in general prices of all 

 commodities and partly to increased demand especially for export, 

 partly also to a shortage of fish for fertilizer, the price went up in 

 1920-21 to Rs. 170 per ton c.i.f. Ceylon, a price which is beyond 

 its calculated manurial value and exceeded that for fish guano. 



145. In South Kanara along the sandy sea coast, sardine manure 

 is largely used for tobacco. But in this case the sardine is used in 

 a wet and putrid condition. Pits are dug in the sand to such 



