372 Natural-Historical Collections. 



he seems little disposed to admit of spontaneous generation ; and if he does not 

 altogether reject it, at least he limits it a good deal more than his master did. 



The most important of the works of Theophrastus, next to his two books up. 

 on botany, is his treatise on stones, a work valuable on account of the number of 

 mineral species that are pointed out in it ; but this treatise is lost. He considers 

 metals as deriving their origin from water, and stones as produced by the earth. 

 He makes a division among stones, distinguishing them as fusible and infusible ; 

 and these last, again, as calcinable stones, aaad stones which are unalterable by 

 lire. He arranges them also according to their hardness and cohesion. He 

 groups all the mineral substances which have a common property, as amber and 

 the loadstone, both of which have a power of attraction. He shov/s the uses of 

 the touchstone, speaks of the diiFerent kinds of petrifaction, and of petrifying 

 waters. 



From these general considerations, he goes to particular descriptions. He 

 ' speaks of different marbles, of the Parian marble, pentelic marble, alabaster, and 

 a good many others that are used by architects and sculptors. He treats of the 

 stones which are reduced for extracting metals, of pit-coal and its different spe- 

 cies. He compares amber with a variety of coal which is found in Liguria, and 

 it is a very just comparison. He mentions also pumice-stones ; he knew their 

 volcanic origin, and gives to one of the species the name of Lipari-stone. He 

 gives a description of the amianthus, which is indestructible by fire ; and of an- 

 other substance, like rotten wood, which, when soaked in oil, burns with a flame. 

 Next come the stones fit for engraving ; the carnelian, the jasper, &c. Mention 

 is made of a sapphire, which has a blue ground, with veins of gold ; it is there, 

 fore not the gem which is now designated sapphire, but the lapis-lazuli. Theo- 

 phrastus speaks of emeralds, and, in doing so, relates, that an Egyptian king had 

 received emeralds from a prince of Ethiopia, which were not less than four cubits 

 in height, and that four of them would have served to erect an obelisk. The 

 thing, though strange, is not altogether incredible ; for it is known that, near 

 Limoges, emeralds are found of very large dimensions, but without either bright- 

 ness or transparency. Besides, the ancients confounded, under the name of eme- 

 ralds, tourmalines and many other green stones. Theophrastus speaks also of 

 the hyacinth ; of the amethyst, which he calls the Heraclean-stone ; of rock- 

 crystal ; of the onyx, which is found on breaking certain rocks ; of the agate, 

 which takes its name from the river Achates ; of the jasper of Bactriana, which 

 is met with among sand. He speaks of the magnetic stone ; and by this name 

 he designates, not what has since been understood by it, the loadstone, but a 

 stone which has no attractive power, of a silvery lustre, and which was then used 

 for making cups. 



In treating of precious stones, Theophrastus speaks also of pearls, but withovkt 

 confounding them with mineral productions. He says that they are got from a 

 shell-fish which is fishe4 in the Indian seas. He speaks of the remains of or- 

 ganized bodies which are found in the earth, of petrified reeds, of fossil ivory, of 

 Armenian blue, &c. 



In treating of the use of mineral substances, he describes the process of Ijie 

 manufactory of glass. He mentions the different colours that painters obtain 

 from minerals ; natural ochre, burnt ochre, white lead, verdigris, vermillion, cin- 

 nabar, which the Phenicians brought from Spain ; it was brought also from Col- 

 chis, and was found, it was said, on the top of certain steep rocks, from which it 

 was separated by the shots of arrows. This was undoubtedly a story invented by 

 the merchants, to warrant their raising its price. Finally, Theophrastus speaks 

 of marl, and its uses ; and of plaster, which, even in his time, was used as it is 

 now, for moulding ornaments for the interior of houses. 

 f To be continued. ) 



