Fish Manures. 13 



ARTICLE II. — Fish Manures. By T. Sterry Huxt. Ex- 

 tracted from the Report of the Geological Survey of Canada 

 for 1857. 



Before describing the results of some enquiries into the value 

 of these manures, and the practicability of introducing their ma- 

 nufacture into Canada, it may be well to explain briefly certain 

 principles which may serve to guide us in the appreciation of the 

 subject. Modern investigations of the chemistry of vegetation 

 have led to a more or less correct understanding of the laws of 

 vegetable nutrition and the theorv ofmanures, and we are all aware 

 how many natural and artificial matters have been proposed as 

 substitutes for the manure of the stable and farm-vard. Foremost 

 among these ranks the Peruvian guano, composed for the most 

 part of the exuviae of sea-birds, and employed for centuries by the 

 Peruvians as a powerful stimulant to vegetation. This substance 

 owes its value to the phosphoric acid and ammonia which it is 

 capable of affording to the growing plant ; the former element be- 

 ing indispensable to the healthy development of vegetation and 

 entering in large proportion into the mineral matter of the cereals, 

 while ammonia furnishes in a form capable of assimilation, the 

 nitrogen, which with the elements of water and carbonic a< 

 makes up the organic tissues of plants. Besides these i ss sntial 

 principles, plants require sulphuric acid, silica, chlorine, potash, soda, 

 lime, magnesia and oxyd of iron, all of which elements are found 

 in their ashes, and are required for their healthy growth. In a 

 fertile soil all of these ingredients are present, as well as phospho- 

 ric aeid and ammonia, which last substance is constantly produced 

 by the decay of animal and vegetable matters, and is either at 

 once retained by the soil, which has the power of absorbing a cer- 

 tain portion of it, or is evolved into the air and afterwards dissolved 

 and brought down bv the rains to the earth. 



Many of the mineral elements of a soil are present in it in an 

 insoluble form, and arc only set free by the slow chemical re-ac- 

 tions constantly going on under the influence of air and wa1 

 Such is the case with the alkalies, potash and soda, and to a 

 certain extent with the phosphates. Now although there is pio- 

 bably no soil which does not yield by analysis quantities of all the 

 mineral elements sufficient for many crops, yet by long and un- 

 interrupted tillage the more soluble combinations of these elements 

 may be all taken up, and the land will then require a certain time 



