Ketc Kind of American Crocorlile. ssj 



The plant in question contains a great deal of tannin. A 

 solution of conmion glue in water, and several o.periment* 

 made in this respeet, have proved it to me \xi a convincinc' 

 manner. 



Having poured into the juice of St. John's wort a little 

 solution of the sulphate of iron, there was formed a prcci- 

 pitr.te of a hlackish hrown colour which liad the property of 

 absorhing oxygen, of becoming at length insoluble in water, 

 and of assuming the characters of a concrete resin. 



St. John's wort contains no e-sential oil. Havinti^ sub- 

 jected a certain quantity of this plant to dis)ili;:ition^ with 

 water, the product of this liquid had a strong and agreeable 

 odour, in which I could discover no trace ot^voiatile oil. , 



The juice of St. John's wort does not dissolve in fat nor 

 in volatile oils, but it combines verv well with resius. For 

 this purpose, having the juice from' the plant, it was poured 

 into flat dishes to be desiccated. This operation may be 

 performed by placing the dishes in an oven some time alter 

 the bread has been taken out : it is then reduced to powder, 

 in which state it may be united to turpentine. This solu- 

 tion is easily effected in a copper mortar which has been 

 well heated. The resin saturated in this manner may be 

 mixed with fat and volatile oils. If combmed with olive 

 oil it forms a medicine known in pharmacy under the name 

 <ii oil of Injpciicum, which when prepared in this manner 

 has decisive properties, and may be emploved with success. 

 When incorporated with linseed oil it produces a beautiful 

 red varnish, which may be used with advantage for furni- 

 ture. 



It is certain that the juice of St. John's wort is a resino- 

 cxtractive substance, in which the resin is considerahlv pre- 

 dominant. The pluenomcna of its solution m water, al- 

 cohol, and resin, and in particular its infliumiiabiiity, suf- 

 ficiently prove it. The last property is so great, that when 

 exposed on a burning coal it burns like incense, and emits 

 very little smoke. It has thepropertv of absorbing the ox- 

 ygen of the atmosphere; it is no way altered in the air; its 

 taste is somewliat bitter, and weakly astringent. 



XL. Accrjiivl of a vcw Kind of American Crocodile. By 

 K. Geoifroy *. 



J. iiK capl all) -general Lcclerc, being informed by some of- 

 ficers of his stair who iiad served in Egypt that the croco- 



* From An>:uks ill! Museum u'liinoiie Kitiirdie, Ni\ 7. 



dilc 



