BETWEEN MURIATIC ACID AND CHLORINE. $33 
forward, in order to bring a little of the salt within the sphere 
of the heat. Great nicety was required in the advancement of 
the sealed extremity ; for the glass tube being perfectly soften- 
ed in its middle, too sudden volatilisation of the salt never 
failed, by inflating and bursting it, to spoil the experiment. 
- This accident frequently happened. On the other hand, if the 
central part of the tube was exposed to merely a dull red, the 
experiment would not succeed with silver and copper. At 
this temperature they did not decompose the sal ammoniac. 
When, however, the above-mentioned precautions were obser- 
ved, dew could be perceived to settle speedily on the cool por- 
tion of the tube. This dew became more and more visible as 
the sublimation advanced, till, finally collecting into distinct 
drops, it trickled down the sides in strize, and formed a fila- 
ment along the bottom. ‘To obtain good results of this kind, 
four or five hours must be devoted to one experiment, in 
which 20 grains of salt, and from 60 to 100 of metal, are em- 
ployed. More rapid transmission of the salts effects mere sub- 
limation. Bubbles of gas come over, which, with silver and 
copper laminz, are found to be a mixture of ammonia and hy- 
drogen. In this case, the liquid condensed, is water of ammo- 
nia. 
The metallic laminz are evidently heavier than before their 
introduction ; but the increase of their weight could not be ex- 
actly ascertained, because a portion of the silver or copper is 
impressed on the inner surface of the tube, giving it a very 
beautiful iridescent and metallic lustre, similar to the colours 
of the diamond beetle, viewed in a microscope. The silver la- 
minz, have for the most part exchanged their native brilliant 
white, for a dull-brown or greyish hue}; and instead of being 
eminently tough and ductile, have become more brittle than 
any substance with which I am acquainted. The slightest 
touch 
