THE FARMER'S MAGAZINE. 



421 



farious practices, that ueither by tlie toiicii, smell, nor the 

 eye, the adulteratiuginatcrials can be detected. It is now 

 a common practice to sift otY the harder lumps in Peru- 

 vian guano, to mix the fine dust most intimately witli ex- 

 tremely finely powdered chalk, gypsum, yellow loam, sand, 

 or whatever the adulterating material may be, and to add 

 afterwards the lumps of genuine guano, so as to give 

 adulterated guano the outward characters of the best Pe- 

 ruvian. The expense to which fraudulent dealers go, in 

 preparing ia a sufficiently fine state the admixtures in 

 order to obtain a perfectlj' uniform powder with the fine 

 guano-dust, is very great ; but if it be considered that 

 often guano worth only 4^ per ton is sold at the full 

 price of the best Peruvian, it will easily be conceived that 

 a good margin for profit is left, notwithstanding the ex- 

 pense. The specimen marked No. I. is a guano which 

 does not contain, [ believe, a particle of Peruvian guano, 

 and is altogether a clumsy imitation. It is surprising 

 that such stuff can find purchasers. This so-called guano 

 consists entirely of fine yellow loam, sand, gypsum, 

 chalk, a little salt, and organic matters poor in nitrogen, 

 since this so-called guano furnishes, on decomposition, 

 little more than 1| per cent, of ammonia. At the utmost, 

 this manure is worth only 31. 3s. per ton. 



No, I. — Compositiou of a sample of guano warranted Peru- 

 vian, but altogether artificially made up, value only £3 3s. 

 per ton. 

 Moisture .. ., ., ., .. .. 7.01) 



* Offfauic matter and aramoniacal salts .. .. 14.56 



Phosphates of lime and maguesia (bone eanh) .. 17 55 



Oxides of iron aud alumina .. .. .. .. 8 82 



Sulphate of lime (gypsum) .. .. .. .. 18.49 



Carbouate of lime (chalk) .. .. .. .. 10.11 



Alkaline salts (common salt chiefly) . . .. .. 6.63 



Insoluble silicious matter (sand) . . . . . . 21.78 



100.00 



Aua. VOELCKER. 



*Containiijg nitrogen .. .. .. 150 



Equal to ammonia .. .. .. .. 1-82 



No. If. is a guauo, which has all the appearance of an ex- 

 cellent sample of Peruvian, but which contains in reality 

 only about one-fourth its weight of genuine Peruvian 

 gnano, and no less than three-fourths its weight of yellow 

 loam and chalk. Instead of 16 per cent, of ammonia, this 

 guauo contains not quite 7 per cent, of ammonia, and 

 scarcely is worth £4 43. per ton : — 



No. II. Composition of adulterated guauo sold at Liverpool 



at £12 per ton. 



Moisture .. .. .. .. .. .. 5.35 



^Organic matter and ammoniacal salts .. .. 16.20 



Phosphates of lime and magnesia . . . . . . 8.48 



Oxides of iron and alumina .. .. .. .. 5.90 



Carbonate of lime .. .. .. .. .. 15.89 



Ma<!ueaia . . . . . . . . , . . . .76 



Alkaline salts (common salt chiefly) . . .. . . 3.10 



Insoluble silicious matter (sand) ., .. ,. 44.32 



100.000 

 Aug. Voelcker. 



* Containing nitrogen .. .. .. 314 



Equal to aa\monia .. .. .. .. 3.82 



This guano contains only one-fourth of its weight of Peru- 

 vian guano and three-fourths of yellow loam and chalk. 

 The specimens marked No. UI. and IV. are not quite so bad 



as the prcccdujg ouea, but etill they are bad taoui;h, and 

 coutain only about one-third of Peruvian guano, and two- 

 thirds of foreign admixtures. In No. III. the chief adul- 

 terating materials are chalk and sand ; in No. IV. there is 

 less chalk and much gypsum, as well as yellow loam and fine 

 coprolite powder. Both guanos are worth about £5 per 

 ton. The following table exhibits the composition of these 

 two adulterated guanos, in contrast with that of genuine 

 Peruvian guano : — 

 Composition of a genuine and adulterated Peruvian g^ano. 



Moisture 



^Organic matter and salts of 

 ammonia 



Phosphates of lime and mag- 

 nesia (bone-earth) . . 



Carbouate of lime (chalk) , , 



Sulphate of lime (gypsum).. 



Carbonate of magnesia 



Alkaline salts 



Insoluble silicious matter 

 (sand) 



*Containing nitrogen 

 Equal to ammonia 



Aug. Voelcker. 

 I have also the ple.i3ure of placing on the table specimens 

 of guauo from the Falkland Islands, Kooria Mooria, inferior 

 Ichaboe, and African guano. By far the most valuable of 

 these is the Falkland Island guano, which, however, 

 is not near so valuable as the beat Peruvian guano, since it 

 coutaiuB much less ammonia. The Kooria Mooria guano is 

 rich in phosphate.?, but, like the sample of inferior Ichaboe 

 guano and the African guano submitted to inspection, poor 

 in ammonia. In comparison with the price of the best Pe- 

 ruvian guano, inferior guanos from other places are gene- 

 rally sold also high. In conclusion I beg to observe that in 

 buying Peruvian guano a farmer requires no other guaran- 

 tee than a letter in which the dealer engages to supply 

 " Peruvian guano, best quality." No expensive analysis is 

 required to test the honesty of the dealer, since a perfectly 

 trustworthy opinion can be given whether the guauo is 

 genuine or adulterated, and the ground of au examination, 

 which the members of this Society have the privilege of ob- 

 taining at the trifling sum of 5s. 



Mr. FrsHER Hobbs expressed the great satisfaction 

 it gave to hioiself, as it would doubtless also give to 

 the other members of the Society, to find their Consult- 

 ing Chemist thus furnishing to the Council, for imme- 

 diate announcement to the agricultural community, the 

 practical result of his researches. He was glad to find 

 that at the small expense of 5s. each member had the 

 privilege of obtaining a certificate of the true value of 

 any substance offered to him for purchase as genuine 

 guano. At Mr. Hobbs's suggestion the thanks of the 

 Council were ordered to be transmitted to Prof. Voelcker 

 for the communications he had then made to them, 

 along with a hope on their part that he would continue, 

 from time to time, as they occurred, to furnish such re- 

 sults of investigations carried on in his laboratory as he 

 might think of immediate practical importance. 



