Chap. 25.] Pernicious Effetts of Cofmetics. 141 



fetid odours, which proceed from putrefying fub- 

 ftances. This feems chiefly to depend on the ful- 

 phureous particles which are exhaled in thofe proceffes, 

 and is illuftrated by a ftriking experiment. If charac- 

 ters are written with a folution of bifmuth on the firft 

 page of a book oT fifty leaves, and the laft page is 

 impregnated with a fmall quantity of the liquid liver 

 of fulphur, a fhort time afterwards the hepatic vapour, 

 carried by the air which circulates between all the 

 leaves, arrives at the other extremity of the book, 

 and converts the colourlefs characters marked on the 

 firft page into a deep brown. It is affirmed that the 

 hepatic gas pafies through the paper ; but it is fuffi- 

 ciently proved that the air carries the gas in this 

 manner from one leaf to another, fince the effect does 

 not take place when the leaves are glued together. 

 This experiment evinces, in the cleared manner, the 

 impermanency of the beautifying effect of the calces 

 of bifmuth. 



The nitrous folution of bifmuth is without colour, 

 and when well faturated affords cryftals without eva- 

 poration. But by evaporation and cooling thefe cryf- 

 tals may always be obtained. The nitre of bifmuth 

 detonates feebly, and with reddilii fcintillations j after 

 which it melts and inflates, leaving a calx of a greenifii 

 yellow colour. This fait expofed to the air lofes its 

 tranfparency, at the fame time that the water of cryfbal- 

 lization is diffipated. 



The acetous acid diffolves bifmuth (lowly, and in 

 fmall quantities. 



Inflammable gas alters the colour of bifmuth, and 

 gives it a violet tinge. Sulphur unites with bifmuth, 

 efpecially with its calx -, in which (late it refembles 

 crude antimony. It unites with all the metals, except 

 zinc and regulus of cobalt, and takes away their mal- 

 leability 



