Guano. 11 



Neither of these two samples, we believe, was purposely adul- 

 terated. The first is genuine Peruvian guano, of an inferior 

 description. The large amount of silicious matter (fragments 

 of granitic rock) no doubt arises from the rock having been too 

 closely scraped in collecting it. 



The second sample, which was likewise sold for Peruvian 

 by a Bristol firm of some reputation, at 121. per ton, however, 

 appears to be a Saldanha-bay guano, of medium quality. 



If the directions given above for calculating the commercial 

 value of manures be followed, it will be seen that the money- 

 value of these different guanos varies considerably. Thus, for 

 instance, whilst the first-mentioned good Peruvian guano is worth 

 in ammonia and phosphates 15/. 35. $>d. per ton, the value of the 

 last-mentioned inferior sample is only 11. 5s. 3d., as the follow- 

 ing calculations show : 



1 ton contains JSfo. I. No. II. 



Ammonia.. .. 385 Ibs., worth 12 17 .. 97 Ibs., worth 3 5 

 Phosphates .. 560 Ibs. 268 ..963 Ibs. 403 



Value 15 38 753 



We thus see that the first is cheap at 127. per ton, whilst the 

 other, sold at the same price, possessed only half the intrinsic 

 value of the first. 



Occasionally farmers are induced to buy guano, offered for 

 sale at a reduction of its market-price, as slightly damaged. It 

 is not safe, however, to invest money in the purchase of a 

 manure of that description, without having ascertained by 

 analysis the amount of damage it has sustained. But especially 

 we would caution the agriculturist to beware of investing money 

 in the purchase of " concentrated guano," " essence of guano," 

 and similarly-named mixtures, which profess to be more valuable 

 than the best Peruvian. Such an issue of guano lately has been 

 analysed by us with the following results : 



Composition of Essence of Guano, sold at 11?. per ton. 



Water .. 8-282 



Organic matter* 13-111 



Phosphates and oxides of iron and alumina f 5-947 



Sulphate of lime (gypsum) 15*179 



Carbonate of lime (chalk) 8'003 



Chloride of sodium (common salt) ... 15-803 



Insoluble siliceous matter, principally sand and 



brickdust 34-297 



100-622 



* Containing ammonia '643 



t Containing phosphoric acid, 1*088 



and equal to bone-earth 2-357 



