sae 

ITS PRODUCTS OF DECOMPOSITION. 81 
ing the bases in solution, collects in the receiver. The decomposition at 250°, 
however, is excessively slow, and even after many days, bases are evolved appa- 
rently in undiminished quantity, but I retained the mixture steadily at this point, 
in hopes of obtaining the product free from ammonia, which my preliminary trials 
had shewn to be produced at higher temperatures; but I found that even with this 
low heat it was evolved always in appreciable, and, in some experiments, even 
in considerable quantity. I therefore gradually raised the temperature to about 
350°, when a larger quantity of base was obtained; and after the heat had been 
sustained for some time, small crystals made their appearance, which deposited 
themselves in a line round the retort, just above the level of the oil in the bath, 
but which soon rose into and collected in the neck of the retort. 
These crystals resemble benzoic acid in their external appearance, and are at 
first perfectly colourless, but soon acquire a brownish shade by exposure to light 
and air. They are a base, and rapidly restore the colour of reddened litmus. 
They are sparingly soluble in water, but readily in acids, and give a precipitate 
with bichloride of platinum. The quantity of this substance obtained was exces- 
sively minute; and though considerable quantities of codeine were operated upon, 
all that was obtained served only to make the few qualitative experiments now 
detailed. 
The watery fluid which collected in the receiver possessed a pungent and 
peculiar smell ; it restored the colour of reddened litmus with great rapidity, and 
gave abundant fumes with hydrochloric acid. On the addition of solid potash, a 
highly volatile and pungent oily base collected as a layer on the surface of the 
fluid, and at the same time a gaseous base escaped along with ammonia. From 
the small quantity of these substances which I was able to obtain, I could not 
attempt to prepare either of them ina pure state. I was therefore under the 
necessity of determining their constitution by the analysis of their platinum salts, 
. which can be separated from one another, though not without difficulty. In 
order to prepare these salts, the basic fiuid was saturated with hydrochloric acid, 
and evaporated to dryness in the water-bath, when it left behind a beautifully 
crystalline mass, highly soluble in water, and deliquescent in moist air. This 
was dissolved in absolute alcohol, to separate ammonia, and the filtered solution 
mixed with an alcoholic solution of bichloride of platinum, when the platinum 
salts were immediately thrown down as a pale-yellow powder, very sparingly 
soluble in absolute alcohol, but readily dissolved on the addition of water. The 
separation of the two bases is best effected by heating the washed precipitate with 
boiling absolute alcohol, and adding water in small quantities until the whole is 
dissolved. The crystals which deposit on cooling are one of the salts in a state 
of purity, if the process have been properly managed, or, at all events, only 
require a repetition of the process to make them absolutely pure. The salt 
thus obtained is scarcely soluble in absolute alcohol or ether, but is readily 
VOL. XX. PART I. % 
