^16 French National Injlitute. 



propofes, with a view of discovering the truth, to make 

 the necefiary refearches and experiments in thofe places 

 ■where the phenomenon has been obferved *. 



In a memoir on a new claffification of (hells, C. Lamarck 

 has (hewn the neceffity of increafing the number of genera, 

 and of abridging the characters by which they are diftin- 

 guiihed. This number he carries to a hundred and Seven- 

 teen. Linnaeus and other naturaliits made it only fixty. 

 By means of this claffification, we may more, eafily reduce 

 to its particular genus, all the teftaceous animals with which 

 we with to be acquainted. 



In the numerous family of the fpiders there are fome 

 called miners and mafons, becaufe they conftruct for them- 

 felves fubterranean cavities or galleries, which they (hut 

 with a kind of trap-door. C. Latreille, affociate of the In- 

 ftitute, has pointed out the characters peculiar to this induf- 

 trious family, and the means of preventing their being con- 

 founded with other infe&s of the fame name, but of a dif- 

 ferent fpecies. 



It is well known that phofphorus, and feveral faline com- 

 binations of the phofphoric acid, have been found by che- 

 mifts in urine. By new refearches C. Fourcroy and Vau- 

 quelin have difcovered, in that liquid, alumine and the phof- 

 phat of magnefia. They have feen that a peculiar animal 

 matter, by which urine is chara&erifed, and which gives it 

 all its properties, forms there, very fpeedily, ammonia, which 

 makes the phofphat of magnefia pafs into the clafs of triple 

 i'alts, renders it much lefs foluble than before, andfufceptible 

 of being precipitated in laminae or cryftalline needles. Thefe 

 two chemifts have given an account of the fpontaneous 

 changes it experiences, and fhewn that the examination of 



* There feems more reafon for fufpefting it to be Prufiian blue, the in- 

 gredients of which are furnifhed by all red blooded animals. Wc may 

 pbferve, however, that it is a known fa£l that cows which eat the madder 



plant, give milk that has the appearance of being llre.ked with blood. 

 Eb»t. 



it, 



