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^XXII.— NOTE ON A SPECIMEN OF ADULTEEATED GUANO 

 EECENTLY ANALYSED IN TEINITY COLLEGE 

 LABOEATORY. By EMIL WEENEE. 



[Eead, December 15, 1886. 



About two months ago I purchased at an establishment in this 

 city a sample of Peruvian guano, the idea at the time being simply 

 to examine the sample for uric acid, and if found comparatively 

 rich in that body to obtain a further supply. The guano, how- 

 ever, on examination proved such an unusual specimen as regards 

 adulteration and general inferiority that, at the request of Dr. 

 Beynolds, I analysed the sample, and now beg to lay the results 

 before the Society. With respect to the uric acid, which is a 

 constant constituent of all good guanos, it was in this case con- 

 spicuous by its absence: not even a trace of it could be obtained 

 when operating on four ounces of the guano. 



So considerable was the adulteration, that, before commencing a 

 complete analysis of the guano, it was necessary to pass it through 

 a coarse sieve, a treatment which resulted in the separation of a 

 quantity of foreign matter, in the form of pieces of granite, shells, 

 &c, to the extent of twenty-five per cent, of the weight of the 

 guano. The composition of the sifted guano is shown in the 

 following analysis: — 



Composition of Guano, previously freed from 25 °/ Adulteration. 



Pixed constituents 

 = 69-30 %, 



Sand, 



CaO, 



P2O5. 



S0 3 , 



K 2 0, 



MgO and nitrates, 



Organic and Volatile f Jf oistl ! re > ++ ' 

 = 40*70 "I 1 V r S amc matter, 



Combined NH 3 , 



24-36 7„ 

 11-65 °/ 

 14-29 °/ 



2-05 °l 



5-13 °/ 



1-82 % 



59-30 °/ 



13-51 % 



22-10 7o, containing nitrogen = 0-02 / o 

 4-94 7. „ „ 3-06 7„ 



40-55 7 



Total nitrogen, . 4'08 J 



As is seen from the analysis, the amount of insoluble matter 

 (sand) is still exceptionally high — nearly twenty-five per cent. : the 



