170 Scientific Intelligence. 



longer in the oven. If the fat has been left in, a kind of cake may 

 be made, of an agreeable taste, and which is more easily kept than 

 that made of butter. When this bread has become dry, it may be 

 pulverised under a rolling mill, and a kind of flour is obtained, very 

 savory and nourishing, and suitable for making a good potage, or for 

 mixing advantageously with other aliments of a less nutritive quality. 

 This flour is easily transported, and contains much nourishment in a 

 small bulk. — Biblioiheque Universelle, Juillet, 1828, 



6. The color of the sea, is ascribed by Sir Humphrey Davy, ia 

 part at least, to the presence of iodine and bromine, which its waters 

 certainly contain, and which result perhaps from the decomposition 

 of marine vegetables. These two substances, dissolved in a small 

 quantity of water, give a yellow tint, and this tint mingled with th© 

 blue tint of pure water may produce the sea green. — Salmonia. 



7. Solar phosphori. — M. Osann has found that a superior phos- 

 phorescent substance is obtained by calcining oyster shells, (selecting 

 for this purpose the whitest and most porous,) and when cleaned 

 placing them in a crucible, previously covering the bottom with finely 

 pulverised sulphuret of antimony, and then alternating the shells and 

 antimonial powder, sifting on the latter to the depth of two lines be- 

 tween each layer of shells. The crucible is then closed and exposed 

 during an hour to a red heat. The superior and inferior strata of 

 shells are commonly soiled, and may be rejected. The phosphorus 

 thus obtained, after having been exposed to the sun, shines in the 

 dark with a greenish white light, and is superior to the Bolognian 

 phosphorus, both in intensity and duration. 



When sulphuret of arsenic (realgar) is substituted for sulphuret of 

 antimony, the pieces shine with a blue light, analogous to the flame 

 of sulphur. In this, as in the preceding, only the places that are per- 

 fectly white are phosphorescent. It presents here and there points 

 which shine with a purple red. If exposed long to a red heat, its 

 light is decolored and becomes completely white. 



These compounds may be preserved in closed vessels. They will 

 remain good for three weeks, if exposed to the air, and it is only 

 when the lime falls into powder that their light is extinct. — Bib^ 

 Univ. Fev. 1829. 



8. Test of the strength of chlorine or chloride of lime. — The so- 

 lution of indigo, which has long been employed in estmiating. the 



