xviii. INTRODUCTION. 



Infusions arc the fittest forms for those liczbs 

 whose qualities are light, and whose virtue is 

 easily extracted ; in this case, hot water poured 

 upon them fa; s up enough of their virtue, and 

 none is lost in the opeiation; olhers require to be 

 boiled in the water. From these are thus made 

 what we call decoctions : and as these last would 

 not give their virtues in infusion, so the others 

 would lose it all in the boiling. It would go 

 olf with the vapour. We know very well, that 

 the distilled water of any herb is only the vapour 

 of the byiled herb caught by proper vessels, and 

 condensed to water : therefore, whether it be 

 caught or let to fly away, all that virtue must be 

 lost in boiling. It is from this, that some plants 

 are fit for decoctions, and some for infusion*. 

 There are some which, if distilled, give no virtue 

 to the water, and these are tit for decoctions, 

 which will retain all their virtue,, as bistort, and 

 tormentill roots, and the like. On the contra- 

 ry, an infusion of mint, or pennyroyal, is of a 

 strong taste, and excellent virtue ; whereas, a 

 decoction of these herbs is disagreeable or good for 

 nothing:. 



There are herbs also, which have so little juice, 

 that it would be impossible to get it out ; and 

 others whose virtue lies in the husks and buds, 

 and this would be lost in the operation. An in- 

 fusion of these is the right way of giving them. 

 Thus mother of thyme is a dry little herb, from 

 winch it would he hard to get any juice, and when 

 gotten, it would possess very little of its virtues : 

 tut an infusion of mother of thyme possesses it 

 entirely. 



Infusions arc of two kinds. They are either 

 prepared in quantity, to be drank cold ; or they 

 re drauk us thev are made, in the manner of tea. 



