CHEMICAL SCIENCE. 267 



parts firmly together, while the iron of the blood forms a sesqui-oxyd, and 

 still further cements the mass. The union of silex and alkali alone pro- 

 duces, in some cases, a very high degree of hardness, as in the case with 

 feldspar, and in this composition are fulfilled all the conditions of a perfect 

 Btone, no element except time being wanted to insure its extreme hardness, 

 strength, and ability to resist the action of the elements. The uses for which 

 this artificial compound seems especially adapted are statues and architectural 

 ornaments, as it may be molded with the same facility as plaster, and grad- 

 ually hardens into a perfect and unchangeable stone. It resembles red sand- 

 stone in color, but may be painted and sanded to conform to any tint desired. 

 Artificial Coral Mr. S. Isaacs, of London, has taken out a patent for 

 making artificial coral, by causing alabaster to be impregnated with oil con- 

 taining red coloring matter, such as madder, after the alabaster has been 

 treated with a very weak solution of sulphuric acid. 



TURKISH EECIPE FOR HYDEATJLIC MORTARS AND CEilEXTS. 



As the aqueducts of Constantinople are attracting additional notice the 

 more they are studied and examined, being astonishing works (especially if 

 we take into account the infant state of chemical and mechanical science 

 among the Turks), the following recipe will be found of interest, and deserv- 

 ing examination and trial. It is, moreover, a curious fact that other semi- 

 barbarous nations, also, are in the possession of mechanical procedures and 

 contrivances, inaccessible even to European science and art ; as, for instance, 

 the art of the Chinese to unite (solder) cast iron, etc. 



Lime Mortar is prepared with fresh water, and mixed with two parts 

 of powdered lime, and one part of river sand. 



Hydraulic Mortar. Bricks are pounded until the grains attain the size of 

 common river sand, and one part of the brick powder is mixed with two 

 parts powdered lime, and the necessary quantity of fresh water. In using 

 this mortar, a layer of mortar is placed between the bricks or courses of 

 bricks of the same thickness of the brick, which must have been previously 

 soaked in water. This latter treatment is never neglected. 



Hydraulic Cement for the internal dressing of arched aqueducts, cisterns, 

 and all constructions through which water flows, or is contained. Take 100 

 ockas (of 2^ Ibs. of 16 ounces) of fluid lime, and twenty-four ockas of very 

 minutely plucked tow, which is to be distributed very accurately throughout 

 the mass. If these two ingredients have been duly mixed and worked up, 

 the mass thus obtained has to remain quiet during at least eight days, that 

 the tow may have time to combine thoroughly with the lime. If the mortar 

 is to be used, it is to be again well stirred up, and is to be spread with a 

 small trowel. For the sake of protecting it still more from the action of 

 water, and to make it durable for a long time, it is then to be coated with a 

 putty which is called lukin. and is thus prepared: To 100 ockas of freshly- 

 burnt lime, which has been converted into dust, 25 ockas of the best linseed 

 oil are added, as well as 20 drachms of rough cotton. The lime is to be 

 worked or mixed in a wooden chest or trough, while the linseed oil and 



