THE TECHNOLOGIST. [May 1, 1864 



442 ON GRANITE AND ITS USES 



remember, is thus described : — " Issacbar is a strong ass couching down 

 between two burdens : and be saw tbat rest was good and the land that 

 it was pleasant ; and bowed bis shoulder to bear, and became a servant 

 unto tribute." This Issacbar, the strong and patient, peaceful bearer of 

 burdens, and servant of his brethren, is the very symbol of industrial 

 science, and he can bear two burdens, so that you need not be afraid to 

 lay one upon him. 



And now, having in a long digression disposed of two grave questions 

 affecting my subject, let me announce the positive truth which I seek to 

 connect with the topic before us : — I was referring to rock crystal as 

 connected with a peculiarly interesting department of technology. 1. 

 As itself a precious stone. 2. As a prominent ingredient of those 

 gems which contain other things besides itself. 3. As occurring along 

 with those most prized. 



There are two famous gems, indeed, perhaps the most famous of all, 

 which are not included among the children of the granite. The one is 

 a choice gift to us from the plant world, viz., the diamond. The 

 flowers have kept the secret of their production to themselves, but they 

 have whispered enough to let it appear that to them we are indebted 

 for that rare crystal, most akin to the light, without which no plant can 

 open its buds or perfect its flowers. The other exceptional gem, the 

 pearl, comes to us from the animal world, and its subdued moon-like 

 splendour, as contrasted with the sun-like diamond, is no unbefitting 

 symbol of the smaller dependence of animals than of plants on the light 

 of day. 



The remaining precious stones are literally stones, the offspring of 

 the rock, and of the earth, earthy. Take for example those mentioned 

 in the Bible, without stopping to question whether or not the names 

 are rightly rendered by our translators, seeing that it is only with the 

 names we have at present to do. 



In Aaron's breastplate there were twelve stones, namely, a sardius 

 (or ruby), a topaz, and a carbuncle ; an emerald, a sapphire, and a dia- 

 mond ;' a ligure (or opal), an agate, and an amethyst ; a beryl, aud an 

 onyx, and a jasper. — (Exod. xxviii, 17, 20.) 



In St. John's description of tbe Heavenly City we read of twelve 

 foundations — jasper, sapphire, chalcedony, emerald, sardonyx, sardius 

 (or ruby), chrysolite, beryl, topaz, chrysoprasus, jacinth, and ametbyst ; 

 " and the twelve gates were twelve pearls, every several gate was of one 

 pearl."— (Rev. xxi. 19-21.) 



Now, omitting the diamond and pearl, and counting no stone twice, 

 we have sixteen gems. But of these, no fewer than one half, namely, 

 agate, amethyst, chalcedony, chrysoprasus, jasper, onyx, opal (ligure), 

 and sardonyx, are slight modifications of silica. Some, like the amethyst, 

 are coloured crystallised rock crystal 5 the others more resemble silica 

 in the form of flint ; but all agree in consisting almost entirely of that 



