Of the Excellent Qualities of Coffee. 635 



effectual way of recommending it would be to explain 

 the mechanical and chemical principles on which its 

 superiority depends. 



In order that the coffee may be perfectly good, the 

 stratum of ground coffee, on which the boiling water 

 is poured, must be of a certain thickness, and it must 

 be pressed together with a certain degree of force. If 

 it be too thin or not sufficiently pressed together, the 

 water will pass through it too rapidly ; and if the layer 

 of ground coffee be too thick, or if it be too much 

 pressed together, the water will be too long in passing 

 through it, and the taste of the coffee will be injured. 



Another circumstance, to which little attention has 

 hitherto been paid, but which I have found to be of 

 considerable importance, is the levelling of the surface 

 of the ground coffee after it has been put into the 

 strainer, before any attempt is made to press it to- 

 gether. 



When the ground coffee is poured into the strainer, 

 it always stands much higher in one part of this vessel 

 than elsewhere ; and, if in that situation it be pressed 

 down on the perforated bottom of this vessel without 

 being previously levelled, it will be much more pressed 

 in some parts than in others ; and, as the water will 

 not fail to pass most rapidly where it meets with the 

 least resistance, a considerable portion of the ground 

 coffee will be so crowded together as to prevent the 

 water from passing through it, and consequently will 

 contribute little or nothing to the strength of the 

 beverage. 



To remedy this inconvenience, I use the following 

 simple contrivance. The circular plate of tin, with a 

 rod fastened to its centre which serves as a rammer for 



