€(>- Scientific Intelligence^ [Jan* 



reality it is tlie agrostis alba, certainly possesses several excellent 

 qualities, and is probably superior to every other for grazing in 

 marshy soils ^ but for hay it is entirely unfit. What Dr, 

 Richardson and others have chosen to call hay, being nothing 

 else than the grass still capable of vegetating. It is this capacity 

 that makes it able to endure wet v^/ithout injury, if it be true 

 that cattle prefer it to hay, we. must ascribe the preference to its 

 continuing always in the state of grass. But this unfitness of it 

 for hay renders it less nourishing than the rye-grass ; for it is 

 generally known, that a given weight of hay is much more 

 nourishing than the same weight of grass. 



The grass usually sown in Sweden is the phleum pratense, or 

 timothy grass, and the Swedish farmers extol it as much softer 

 and more agreeable to the taste of cattle than rye-grass. How 

 far it possesses these qualities 1 do not know ; but its lateness is 

 an insurmountable objection to its being introduced into this 

 country as an artificial grass ; as from it no second crop after 

 the first cutting could be expected. Perhaps in Sweden, where 

 the summer is shorter than in England, this objection may not 

 be of so much consequence ; but in England it must be fatal to 

 tjie introduction of the grass as an object of general culture. 



IV. Egg-Shells. 



Vauquelin has lately examined the constituents of egg-shells, 

 with more care than had been bestowed on them by former 

 chemists; and has found them to consist of the following sub- 

 stances : carbonic acid^ lime, magnesia, phosphate of lime, 

 iron, sulphur, and an animal matter which acts as the cement. 

 It is probable, that the lime and the magnesia are combined with 

 carbonic acid. The sulphur seems to be in combination with the 

 animal matter. The state in which the iron exists in egg-shells 

 has not been ascertained. The membrane which lines the in- 

 ternal surface of the egg-shell seems to be coagulated albumen : 

 at least it dissolves in potash without the evolution of any am- 

 monia. Vauquelin detected magnesia, phosphate of lime, and 

 iron, likewise in oyster-shells; but the proportion of these sub- 

 stances was much smaller than in egg-shells. All his attempts 

 to detect uric acid in egg-shells were unsuccessful. 



V. Gunpowder, 



Gunpowder is usually composed of the following constituents i 



Nitre , 76 



Charcoal 15 



Sulphur 9 



There can be no doubt that the sulphur contributes very ma- 

 terially to the good qualities of the powder, though it is difficult 

 to form m idea uf the chemical effect which it produces. Proust 



