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all decomposing animal matters, therefore its presence is readily ac- 

 counted for). If we reflect that the guano is the excrement of birds 

 which scarcely ever fly on land to obtain food, therefore their support 

 is to be found in the plants or animals of the sea, and it is almost ex- 

 clusively from the latter that they derive their food, consequently the 

 elements of their excrement must be contained in the bodies of the 

 fish. Then again, if fish have the elements of sulphate of potash in 

 their systems, how do they obtain it ? In the ocean in which they 

 swim, potassium is found combined with chlorine, forming about 

 iwff P ar t pf * ne whole. Sulphuric acid exists combined with mag- 

 nesia and lime in somewhat larger proportions. Notwithstanding 

 these exist in the water in such limited quantities, we are not to ima- 

 gine that the fish derive any nutriment from the water any more than 

 we do from the air, both elements serving essentially as the medium 

 for supplying the oxygen for respiration. As fish undoubtedly either 

 devour small animals or some of their species, and these, again, live 

 on the vegetable materials found growing in the ocean, we ought to 

 have the elements of this saline matter in such plants. According to 

 the researches of Fordhammer in his paper read before the British 

 Association in 1844, he has found potash in all sea-weeds ; and re- 

 marks it as a singular fact, that notwithstanding there are forty times 

 as much of the salts of soda in sea- water as of potash, the vegetable 

 beings that grow in the ocean appropriate the latter to form a part of 

 their tissue and refuse the former, which appears to be merely dis- 

 solved in the juices of the plant. Therefore we can trace the source 

 of potash in the food of fishes, but we have yet one step further to 

 retrace : from whence is the ocean supplied by this substance ? Ford- 

 hammer has asserted that the small dewdrops that condense on the 

 mountain, and become reinforced by others until they make the first 

 streamlet, and also the rain that falls on the face of the earth and per- 

 colates the soil, both dissolve the saline matters in their course, till 

 they reach the brook that conducts the waters to the tributary of some 

 great river, when ultimately all the materials that are dissolved from 

 the soil are mingled with the waters of the ocean. 



Thus it would appear that there is a complete circle in many of 

 the operations of Nature and of man, for since the discovery of the 

 valuable properties of guano as a manure, by distributing it over the 

 surface of the land, we are actually restoring the elements that had 

 been removed by the rain, and which after a variety of changes in the 

 system of vegetables and animals, are singularly restored to the earth 

 from which they were first derived. 



