Miscellaneous Results from the Laboratory. 



611 



to a longer distance than their perishable nature will now admit. They 

 were first examined in the year 1847, and, to ascertain that their composi- 

 tion was not variable, a second time in the following season, Decem- 

 ber, 1848.* 



In all cases a sufficient number of fish was operated upon to ensure an 

 average result. They were bruised in a mortar, and then dried at the 

 temperature of boiling water ; from the dry mass, the oil or fat was ex- 

 tracted by digestion with ether; after which, the residue, again dried, was 

 analyzed for nitrogen. The mineral matter was obtained by burning a 

 quantity of the sprats previously dried. Thus examined, they were found 

 to yield in 100 parts : — 



Sprats of 1847. Sprats of 1848. 



Water 64-60 63-65 



Oil 19-50 .. 18-60 



Dry Nitrogenous matter . 15*90 17*75 



100-00 100-00 

 The specimen of 1847 was not examined for nitrogen ; that of 1848 was. 

 The dry matter (after separation of the oil) gave : — 



Per Cent, 

 of Nitrogen. 



First experiment 11*75 



Second experiment • . . . 11 '31 



Mean 11-53 



Upon this datum it will be found that the sprats in their natural condi- 

 tion contain 1*94 per cent, of nitrogen. The quantity of mineral matter 

 obtained by burning the fish was — 



Sprats of 1847. Sprats of 1848. 

 Ash per cent, on the natural fish . . . .2*12 2*10 



A result which is identical for the two years. These ashes had the fol- 

 lowing composition : — 





Sprats of 



Sprats of 





1847. 



1848. 





traces 



•30 



Phosphoric Acid .... 



43-52 



40-49 



Sulphuric Acid .... 



traces 



1*40 



Carbonic Acid 



none 



none 





23-57 



27*23 





3-01 



3*42 



Peroxide of Iron 



•28 



•65 





17*23 



21-89 





1*19 



none 



Chloride of Potassium . . 



none 



2*31 



Chloride of Sodium . 



11*19 



2*31 



Total .... 



100-00 



100-00 



1000 grs. of the fish in its natural state, when examined directly for sulphur, gave 

 1 . 50 grs. 



This ash is precisely what we should expect to find it — the phosphate 

 of lime being furnished by the bones, and the potash by the fleshy sub- 

 stance of the fish. 



It is worthy of remark, that the quantity of potash should be so consi- 



* I am told that there is a marked difference between the fish of the early and late 

 months of the season ; they are at first plump and fat, and subsequently become 

 shrivelled and lean, when they would probably contain much less oil. 



