1 84 



MADRAS FISHERIES BULLETIN 



VOL. XIII, 



The following table shows the percentages of lime, nitrogen, 

 phosphoric anhydride, fat, and water present in these three samples 

 of fish guano from South Malabar, compared with the correspond- 

 ing figures recorded for fish manure from other sources : — 



The maximum contents of nitrogen in a Tanur sample was 9*34, 

 a very good percentage. American menhaden guano (" scrap ") is 

 said by Stevenson to contain usually about 8 per cent nitrogen and 

 8/^ per cent phosphoric acid. Other analyses give an average of 

 about 8'3 nitrogen and somewhat less phosphoric acid with about 7 

 per cent moisture (unusually low for a bulk sample) and 7"3 of 

 oil. Japanese herring (iwashi) guano is said in certain analyses 

 to contain as much as 10*6 of nitrogen but only 5"5 of phosphoric 

 acid, a very low percentage, 6 per cent of oil, and 10*2 per cent of 

 water. 



77. The contents of oil (fat) in the dry guano are considerable; 

 the wet stuff is somewhat glutinous and it is difficult, especially 

 with only manual presses, even to get rid of much of the water; 

 still more difficult to express all the oil- The oil in the samples 

 tabulated above average 6'86 per cent for Tanur guano, and this 

 agrees with about 7 per cent in menhaden scrap (Imperial In- 

 stitute Bulletin No. 3 of 1914) and 6 per cent in some Japanese, 

 herring guano. Possibly the best menhaden scrap contains less 

 oil than is here stated, since the presses used are of enormous 

 power; on the other hand Madras guano in general probably con- 

 tains a larger percentage as the pressure is inferior. 



The amount of water in dry guano has been mentioned in para- 

 graph 75 and does not exceed 8 per cent in good West Coast guano. 

 With this small quantity of water the guano is fully dry in a com- 

 mercial sense and will, so far as moisture is concerned, keep, 

 perfectly goodi even in bulk, for an indefinite time. 



