Mo. 3 (1921) MANUFACTURE OF FISH OIL AND GUANO 239 



is as useful as the oil ; more so in the matters of lubrication and 

 greases, for hydrogenation, etc. Hence, except for edible and 

 medicinal purposes, the fish oils are usually sold cum-stearine. 



FISH MANURE. 



140. This name is applied to the fertilizer produced by simply 

 drying the whole fish (sardine) on the sandy beach instead of 

 boiling it for oil and guano ; it is an old method of utilizing — even 

 for food — the masses of sardine which are frequently brought 

 to shore and which for lack of time and means cannot be 

 properly cured. The fish is simply spread in layers in the sun 

 on the loose sand, turned over occasionally, and, after some 

 days, when dry, is stored and sold. No salt whatever is used, 

 so that the ungutted fish is tainted long before it is dry ; if 

 the weather is cloudy or rainy it may remain on the beach literal- 

 ly for weeks, and, while thus forming a grave nuisance, loses 

 much of its value by the natural evolution of ammonia and by the 

 attacks of insects, birds, and dogs innumerable ; on unfavourable 

 occasions little but scale and bone is left. Another source of 

 damage is the unavoidable admixture of sand, especially when 

 fish are fat ; the oil is liquified by the heat and then dries on the 

 exterior, so that quantities of sand adhere to the fish and a great 

 deal is added when scraping them together. The purchasing 

 firms allow for 1 5 per cent of sand in their contracts, dtducting 

 further for any excess, but, usually from fraud, the admixture often 

 far exceeds that percentage ; in 15 invoices of 1911 — 13 taken at 

 random, the amount varied between 15 and 33 per cent and in 

 one case, seen in London, the sand was 44 per cent of the parcel. 

 This matter is dealt with more, in detail in the annual reports of 

 the Fisheries Department ; see Bulletin No. X, pages 35 and 36, 

 etc., and below s.v. " adulteration." 



141. Considering all these sources of loss it is not surprising 

 that the manurial contents, nitrogen and phosphoric acid, are 

 somewhat low, usually about half the normal contents of the 

 whole fresh fish. 



As noted above (paragraph 82), while a large firm guaranteed 

 8 to 9 per cent nitrogen and 7 to 8 per cent phosphoric acid in 

 boiled and pressed fish guano which they priced at Rs. 100 per 

 ton, they only guaranteed 5 to 6 per cent and 4 to 5 per cent, 

 respectively, for " milled " fish (ground and to a large extent freed 



