70 ESSAY V. 



examine it in its elastic state. Common muriatic acid is 

 to be mixed with levigated manganese in any quantity in 

 a glass retort, which is to be put into warm sand, and a 

 glass receiver applied, capable of containing about 12 oz. of 

 water. Into the receiver put about 2 drms. of water ; the 

 joints are to be luted only with a piece of blotting paper tied 

 round them. In a quarter of an hour, or a little longer, a 

 quantity of elastic acid, going over into the receiver, gives 

 the air contained in it a yellow colour, and then it is to be 

 separated from the retort. At this time, if the paper has 

 been closely applied, a portion of the aerial fluid will rush 

 out with some force ; and you therefore must have a cork 

 ready to close it immediately ; and then another receiver, 

 with 2 drms. of water in it, should be applied to the retort 

 as before ; and thus several such vessels may be filled with 

 dephlogisticated muriatic acid. In the process care should 

 be taken that the retort be fixed in such a posture, that if 

 a few drops should rise into its neck, they may run back 

 into the body. The water put into the receivers serves to 

 condense the vapours of marine acid should any go over. 

 I fill several glasses at once, in order to get a good quantity, 

 and to avoid the trouble of repeating the process as often 

 as I want some of the fluid for my experiments. It is 

 better to make use of small vessels for receivers, because 

 a great part of the acid is lost every time the cork is taken 

 out. 



SECTION XXV. 



The bodies which I wished to expose to the action of 

 this dephlogisticated aerial fluid were fixed in a glass tube 

 which passed through the cork of the receiver. I observed 

 that the corks (a) became yellow within the receiver, as 

 from aquafortis, and the lute was likewise corroded during 



