ON A SWEET AND VOLATILE MATTER 263 



this inspissated matter be strongly heated, the vapours that 

 arise will take fire on the application of a candle. In order 

 to make it pass over from the retort into the receiver, a 

 degree of heat is requisite equal to that which must be 

 employed for the distillation of vitriolic acid. Half of the 

 sweet matter goes over unaltered, in the form of a thick 

 syrup, and still retains its sweet taste ; what rises afterwards 

 has an empyreumatic smell, and this is followed by an oil of 

 a brown colour, which smells like spirit of tartar. There 

 remains in the retort a light spongy coal, which does not 

 contain the smallest particle of lead. This sweet matter 

 cannot be made to crystallise ; nor, when mixed with water 

 and set in a warm place, does it run into fermentation; for, 

 after the mixture had stood for four months, tincture of 

 turnsol did not undergo the least change when mixed with 

 it. It will mix with tincture of caustic vegetable alkali, 

 though neither simple syrup nor honey will do this ; but 

 they attract the alkaline salt from the spirit of wine, and 

 then fall to the bottom, in the form of a thick mucilage. If 

 nitrous acid be abstracted from off this unctuous sweet 

 substance, it is at last, after many repetitions of the operation, 

 converted into acid of sugar, and the nitrous acid is very 

 much phlogisticated. It would seem to follow from these 

 experiments, that the sweet matter in question is combined 

 with more of the principle of inflammability than sugar and 

 honey. 



I have also boiled litharge with olive oil separated from 

 soap by vitriolic acid, with the same result ; for I here 

 likewise obtained the sweet matter. I likewise separated 

 the oil from the common salve (empl. simp. 1 ) ; which must 



1 The author means, undoubtedly, the emplastrum commune of the 

 Pharm. tiuecica, in which there is no salve with the denomination simplex. 

 The empl. comm. is prepared from two parts of oil of olives and one of 



