526 



THE POPULAR SCIENCE MONTHLY. 



production of the eye, but only the growth 

 of buds marked with a black point, and, in 

 one case, of opaque bifid buds in place of 

 eyes. The author promises at an early day 

 to communicate to the Academy his obser- 

 vations on certain concretions formed in the 

 stomach of the crawfish, and called crab's 

 eyes in old pharmacopoeias. 



The Amarantus Blitum. M. Boutin's 

 observations on the Amarantus blitum, brief- 

 ly alluded to in a late number of the Month- 

 ly, are so important as to call for a fuller 

 statement. The amarantus belongs to the 

 order Amaranlacece, which contains nearly 

 300 known species. Some of these are fa- 

 miliar annuals in flower-gardens. The Ama- 

 rantus blitum is a weed growing abundantly 

 in many parts of Europe, and has never 

 hitherto been supposed to possess any prop- 

 erties of economical value. Boutin's atten- 

 tion was first called to this plant on seeing 

 it employed in scouring brass utensils. He 

 supposed that it must contain some free 

 acid or some acid salt. He found with 

 surprise that it was completely neutral, and 

 contained only nitrate of potash (saltpetre). 

 To determine the proportion in which this 

 salt enters into the constitution of the ama- 

 rantus, he reduced to ashes 100 grammes 

 (between 3 and 4 ounces) of the dried plant. 

 The 16 grammes of ashes were treated with 

 warm distilled water, and the whole then 

 thrown into a filter. Having washed well 

 the insoluble portion which remained in the 

 filter, the author evaporated the filtered 

 liquid, and so obtained a residue of carbo- 

 nate of potash, 8 grammes. This weight 

 of the carbonate is the equivalent of 11.68 

 grammes of the nitrate of potash, or salt- 

 petre. The insoluble portion remaining in 

 the filter would, on desiccation, give a 

 weight equal to that of the carbonate ob- 

 tained, or 8 grammes, to make up the ori- 

 ginal 16 grammes of ash. This insoluble 

 portion consisted of lime, oxides of iron, 

 alumina, and silica, with a small amount of 

 phosphate of potash. 



The author remarks upon the impor- 

 tance of this plant as a manure. It is su- 

 perior to guano. And, if from any cause the 

 supply of nitre for the manufacture of gun- 

 powder were cut off, this plant could readily 

 furnish it in any quantity. The question 



now arises, whence does the amarantus di- 

 rectly derive its nitrogen from the soil or 

 from the atmosphere? In the spring of 

 1872 the author had a plot of ground 

 broken up with the spade, to a depth of 

 about 8 inches, and kept free from all vege- 

 tal growth during the entire summer. This 

 ground was in a condition to receive all the 

 nitric acid and ammonia produced in the 

 atmosphere by electricity. Yet, on a very 

 careful analysis, no appreciable quantity of 

 the nitrate could be found. On the other 

 hand, the amarantus growing in the imme- 

 diate vicinity yielded the usual amount 10 

 to 12 per cent, of the dried plant. Hence 

 the author concludes that plants derive their 

 nitrogen directly from the atmosphere. 



Discovery of Ancient Egyptian Mines. 



Some of the iron-mines anciently worked 

 by the Egyptians have recently been dis- 

 covered anew by English explorers, and 

 search is to be instituted for other an- 

 cient mines of silver, gold, and iron. As 

 the processes followed in ancient times for 

 the reduction of ores were very defective, 

 it is expected that, in the debris accumulated 

 in the neighborhood of the mines, an 

 amount of the useful and precious metals 

 will be found sufficient to make the work- 

 ing it over again profitable. At a recent 

 meeting of the British Society of Antiqua- 

 ries, mention was made of the discovery, in 

 the neighborhood of Mount Sinai, of the tur-. 

 quoise-mines of the ancient Egyptians. The 

 discoverer, an Englishman, whose name is 

 not given, observed in the water-courses of 

 that region, which in summer are dry, pecul- 

 iar blue stones which he soon ascertained 

 to be turquoises. This circumstance led to 

 further research. We are now informed 

 that, " aided by the friendly tribes he has 

 taken into his pay, he has discovered the old 

 turquoise-mines of the ancient Egyptians, 

 the rocks that they worked for the stones, 

 the very tools they used, and their polish- 

 ing and grinding places." The fortunate 

 discoverer has already sent to England 

 some of the finest turquoises ever seen. 



While searching for the turquoise-mines, 

 this same explorer discovered the ancient 

 lines of fortification surrounding the works, 

 and came upon the remains of vast iron- 

 works, which must have employed many 



