118 CEMENTS. 



CELERY. This vegetable, beside its uses as an accom- 

 paniment to white fowls and for salads, is often dressed as 

 asparagus, boiled, cut into pieces of six or seven inches, 

 and served on buttered toast. It is also cut in small pieces 

 and stewed in butter, and a little pepper and salt added, 

 and cream sauce poured over it just before it is sent to the 

 table. Celery and celery seed make a nice flavoring for 

 light soups. 



CEMENTS. The substances * which form the uniting 

 medium between bricks and stones in building are called 

 cements. The best calcareous cements are those which are 

 equally mixed, and of good consistence, and are manufac- 

 tured of pure lime, freed from carbonic acid by recent slack- 

 ing, and sand which is fresh (as salt is apt to deliquesce, and 

 weaken the strength of the cement), and whose angles are 

 sharp, not worn by the action of tides and water. 



The proportion of sand and lime is different in various 

 cements, but that of sand always exceeds the lime, and the 

 more sand the lime can receive, and retain at the same time 

 the required plasticity, the better for the cement, as it solidi- 

 fies sooner, when the well worked and beaten lime and 

 water is subdivided, and well taken up with clean sharp 

 sand. The purer the lime, and the more it is worked and 

 beaten, the greater its capacity for receiving sand. 



Common mortar is made of pure lime, in the state of fine 

 powder, good sand free from clay, and a little pure water. 

 It is customary to have the sand partly coarse, and the usual 

 proportions are three parts of fine and four parts of coarser 

 sand, and one part of quicklime, recently slacked with pure 

 water, to reduce the whole to a thick paste. 



Water, hydraulic, or Roman cements are those which 

 resist the action of water, hardening under it, and solidify 

 very soon after being mixed. They are formed of various 

 substances. 



