612 Miscellaneous Results from the Laboratory. 



derable, not as a physiological fact of an unexpected character, but in 

 relation to the composition of guano, which is in reality produced from 

 fish, having probably a chemical character very closely allied to that of 

 those we are discussing. It will be remembered that in guano, according 

 to analyses I had the honour of publishing in this Journal, the per centage 

 of phosphoric acid being 25' 0, that of potash was shown to average 3*5, 

 or about l-7th. In the original fish, however, if we may judge by the 

 present analysis, the relation is more nearly as 2 to 1 ; so that in the pro- 

 duction of guano, three parts out of four of the potash disappear. This 

 peculiarity is mentioned rather as curious than as of any importance. 

 The size of bone in the fish in relation to its flesh might possibly account 

 for the above-named circumstance ; but of this I have no means of judging. 



As a matter of more practical importance, I would draw attention to 

 the similarity in composition between some of our cultivated crops and 

 that of sprats. Wheat, for instance, contains about 2 per cent, of nitrogen ; 

 so does this fish. 100 lbs. of wheat require about If lbs. of ash, of which 

 about one half is phosphoric acid, and l-3rd potash, 100 lbs. of sprats 

 contain 2 lbs. of ash, of which 2-5ths is phosphoric acid, and l-5th potash. 

 What manure should be more fit to produce a bushel of wheat than ^ cwt. 

 of sprats ?* 



Indeed, there is nothing surprising in this resemblance. The composi- 

 tion of sprats would probably be found nearly identical with that of any 

 entire animal examined in the same way. 



We know that wheat contains everything that is necessary to support 

 life and to increase the animal frame ; in other words, it is identical or 

 nearly identical in composition with the body which it nourishes. Sprats 

 then may be taken as the type of animal — wheat as that of vegetable life, 

 and there can be no doubt of their mutual convertibility, when placed in 

 the proper circumstances. 



I have dwelt upon this point in order to show how very valuable a 

 source of manure, and consequently of food, we have in the waters that 

 surround our shores, if we could work out the problem as one of economy. 

 Practically we do so at this day, by bringing guano, which is digested fish, 

 from far distant parts. 



The use of fish manure is very limited, being confined to within a cer- 

 tain distance of the sea-shore, and this for obvious reasons. In the first 

 place, it requires to be used in large dressings, although it is, weight for 

 weight, at least four times as powerful as farm-yard dung ; consequently 

 the expense of carriage, added to its original cost, soon places a limit to 

 the transportation of this kind of manure. Secondly, it will not keep for 

 any length of time ; and at whatever season it is taken, it must be at once, 

 or within a few days, applied to the ground. This is another serious draw- 

 back to its employment. The third and last objection which we shall 

 bring against the employment of sprats as a more general manure, is the 

 great uncertainty of the collection ; in some seasons being very scarce, in 

 others so abundant that it pays the farmer to send his waggons 20 or 30 

 miles for them. 



t stated that my motive for examining sprats was to ascertain whether 

 by any means they could be preserved and concentrated for transportation. 

 I was unprepared at the time for the discovery of so large a per centage 

 of oil in the fish ; but it immediately occurred to me that the circumstance 

 might render it possible to make them more generally available for ma- 

 nure. 



So far as we know, oil is of no value as manure, or at all events of a 



* That is to say, supposing that in the production of wheat no loss of manure occurs, 

 a supposition which is rendered very doubtful by Mr. Lawes' experiments. 



