DR DUNCAN on Mudarine. 437 



dually liquefies in the portion of fluid in contact with it, with- 

 out passing through the intermediate form of a jelly. 



The coagulum, when separated from the fluid, is a transparent 

 brown mass, exceedingly brittle, not deliquescent, fragments an- 

 gular, lustre resinous, taste bitter, nauseous, adhering to the 

 teeth. 



In this state it seems at first not to be soluble in distilled 

 water, but after some days it is dissolved in it, with the same 

 phenomena as in the fluid from which it was separated by boil- 

 ing, and the solution has acquired its original properties. The 

 dry mudarine is readily soluble in rectified spirit, and is not pre- 

 cipitated from the alcoholic solution by the addition of water. 

 As long as any considerable proportion of spirit remains, it is 

 not coagulated by increase of temperature, but, on allowing the 

 spirit to evaporate by exposure to the air, it remains dissolved in 

 the water, and has reacquired its original properties. 



It would therefore seem that its tardy solubility, after being 

 contracted, is owing to the state of increased aggregation, for 

 when this is removed by alcohol, its solubility is quickly re- 

 stored. 



Mudarine is also extracted, by the action of cold water, from 

 the powder, but it is not so easily separated from a gummy mat- 

 ter, also dissolved, as from the resin extracted along with it by 

 rectified spirit. 



Its presence is, however, sufficiently demonstrated by the 

 cold infusion gradually losing its transparency as its tempera- 

 ture is increased, and in this case it regains its former transpa- 

 rency, even after having been subjected for some time to the 

 boiling temperature. 



We therefore see, that, in this instance, a very active princi- 

 ple is more readily dissolved by cold than by boiling water ; and 

 it is probable that there are other instances in which heat is im- 

 properly employed, with the view of extracting the active princi- 

 ples of vegetable substances. 



3i2 



