622 Of the Excellent Qualities of Coffee. 



it is not controlled by the laws ; and, if a government 

 is seriously disposed to encourage the general use of 

 coffee, individuals must be permitted to roast it in their 

 own houses. 



As the roasting and grinding of coffee take up some 

 considerable time, and cannot always be done with- 

 out inconvenience at the moment when the coffee is 

 wanted, I contrived a box for keeping the ground 

 coffee, which I have found by several years experi- 

 ence to preserve the coffee much better than any of 

 the vessels commonly used for that purpose. It is a 

 cylindrical box made of strong tin, four inches and a 

 quarter in diameter and five inches in height, formed 

 as accurately as possible within, to which a piston is so 

 adapted as to close it very exactly, and when pressed 

 down into it to remain in the place where it is left, 

 without being in danger of being pushed upwards by 

 the elasticity of the ground coffee, which it is destined 

 to confine. 



This piston is composed of a circular plate of very 

 stout tin, which is soldered to the lower part of an 

 elastic hoop of tin, about two inches wide, which is 

 made to fit into the cylindrical box as exactly as pos- 

 sible, and so as not to be moved up and down in it 

 without employing a considerable force. This hoop is 

 rendered elastic by means of a number of vertical slits 

 made in the sides of it. 



On the upper side of the circular plate of tin which 

 closes this hoop below, and in the centre of it, there 

 is fixed a strong ring of about one inch in diameter, 

 which serves instead of a piston-rod or a handle for 

 the piston. The cylindrical box is closed above by a 

 cover which is fitted to it with care, in order that the 



