Of Coffee, and the Art of preparing it. Ill 



a strong ring, ot about one inch in diameter, which serves 

 instead of a piston rod, or a handle for the piston. The 

 cylindrical bi^x is closed above by a cover, which is fitted 

 to it with care, in order that ihe air which is shut up 

 within the box (between the piston and the cover) might 



be well confined." 



*' Boiling hot w ater extracts from coffee, which has been 

 proper! V roasted and t' round, an aromatic substance of an 

 exquisite flavour, together with a considerable quantity of 

 astringent matter, of a bitter but very agreeable taste; but 

 this aromatic substance, which is supposed to be an oil, is 

 extremely volatile, and is so feebly united to the water 

 that it escapes from it into the air with great facility. If a 

 cup ot the very best coffee, prepared in the highest perfec- 

 tion, and boiling hot, be placed on a table, in the middle 

 of a large room, and suffered to cool, it will in cooling; fill 

 the room with its fragrance ; but the coffee, after having 

 become cold, will be found to have lost a great deal of its 

 flavour. If it be again heated, its taste and flavour will be 

 siill further impaired ; and after it has beeii heated and 

 cooled two or three times, it will be found to be quite vapid 

 and disgusting. The fragrance diifused through the air is 

 a sure indicaiion that the coffee has lost some of its most 

 volatile parts ; and as that liquor is found to have lost its 

 peculiar flavour, and also its exkilarat'mg quality, there can 

 be no doubt but that both these depend on the preservation 

 of those volatile particles which escape into the air with 

 such facility." 



" In order that coffee may retain all those aromatic par- 

 ticles which give to that beverage its excellent qualities, 

 nothing more is necessary than to prevent all internal mo- 

 tions among the particles of that liquid ; by preventing its 

 being exposed to any change of temperature, either during 

 the time employed in preparing it j or afterwards, till it is 

 served up. 



"This may bedone by pouring boiling water on the cofTee 

 jn powder; and surrounding the machine in which the 

 coffee is made, by boiling water; or by the steam of boiling 

 water: for the temperature of boiling water is invariable^ 

 (while the pressure of the atmosphere remains the same,) 

 and the temperature of steam is the same as that of the 

 boiling water from which it escapes. 



*' But the temperature of boiling water is preferable 

 to all others for making coffee, not only on account of 

 its comlntiaj, but also on account of its being most 

 fa/our^ble to the extraction of all that is valuable in 



the 



