594 



NA TURE 



[April 21, 1898 



.ative principle of the yeast, whatever it may be, must possess a 

 corresponding or complementary configuration, and so be able 

 to come into very close relation to the molecule of the sugar it 

 ferments, much as a key can only unfasten a lock for which it is 

 constructed and to whose parts its own shape corresponds. The 

 configuration of the two fitting as it were into each other, the 

 disruption of the sugar molecule by the action or possibly vibra- 

 tion of the fermentative principle becomes conceivable. 



Fischer does not base this hypothesis upon supposition merely, 

 but has tested it by studying the action of some of the soluble 

 enzymes upon the bodies they attack. His results with inver- 

 tase are very interesting. According to Van 't Hoff's stereo- 

 chemical theory, there are possibly to be found two methyl- 

 glucosides, a and /3, which differ only in their configuration. 

 Fischer synthesised both these bodies and heated a quantity of 

 each with 20 times its volume of invertase solution to 30-33° C. 

 At the end of some time about half of the a body was hydrolysed, 

 yielding glucose as one of its products. The & body underwent no 

 change. Yet the two methyl-glucosides have the same composi- 

 tion, are formed from the same alcohol (methyl alcohol) and 

 from the same sugar (glucose), and differ only in the configuration 

 of a single carbon atom rendered asymmetric by the introduc- 

 tion of the methyl group into the sugar. 



The great advances made in the study of fermentations under 

 the action of soluble enyzmes during late years, has drawn the 

 attention of many to the possibility of the secretion of an alcohol- 

 producing enyzme by the yeast cells. It is evident that the intro- 

 duction of the idea of an enyzme need not involve a new view 

 as to what fermentation itself is. It is only necessary to sub- 

 stitute the secreted enzyme for the protoplasm of the cell, as the 

 active agent in the process. 



The idea was advanced some time ago by Berthelot, who 

 compared both lactic and alcoholic fermentations to the con- 

 version of starch into sugar. It has also been suggested by 

 Moritz Traube and by Hoppe-Seyler. 



The enyzme has, according to Buchner, actually been prepared 

 from very active yeast by grinding the cells and squeezing the fluid 

 contents from the resulting mass under the very heavy pressure 

 of 500 atmospheres to the square inch. 



As a review of Buchner's work appeared in this journal com- 

 paratively recently, it is not necessary to recount his experiments 

 in detail. 



The discovery, should it be confirmed, deals a very heavy 

 blow to the vibration theories of fermentation due to Liebig and 

 Naegeli. Their views are only tenable on the theory that most, 

 if not all, of the action takes place in the liquid outside the cells. 

 If Buchner is correct, and the work is done by means of an 

 enzyme, it must necessarily be intra-cellitlar, for enzymes, so far 

 as they have at present been investigated, show no tendency to 

 diffuse through such a membrane as the cell wall. It also 

 militates against Pasteur's theory of intramolecular respiration, 

 which demands the idea of the decomposition being brought 

 about by chemical action between the protoplasm and the body 

 from which it, according to the theory, obtains its oxygen. 



J. Reynolds Green. 



THE METALS USED BY THE GREAT 

 NATIONS OF ANTIQUITY} 



A T the beginning of this century little was known of the great 

 -^ nations of antiquity, except through the classic poets and 

 historians, and the sacred writings of the Hebrew people. Since 

 then our knowledge has been enormously increased by the labours 

 of scholars and explorers ; the ruins of ancient cities have been 

 exhumed, and the contemporary literature of Egypt and Assyria, 

 inscribed on papyri or tablets of clay, and painted or carved on 

 the- walls of temples, palaces and tombs, has been deciphered. 

 What is in some respects still more important is, that objects 

 found in these ruins have thrown great light upon the daily life 

 of the people, and their ornamental and useful arts. One of the 

 departments of this inquiry concerns the metals used by the 

 different nations, and at the different epochs of their history; and 

 it is to this that my attention will be confined this evening. The 

 difficulty I experience is the vast amount of material ; and I 

 cannot attempt anything more than a general view of the subject, 

 and some of the most salient points. 



The area over which the inquiry extends is that of the lands 



1 A Friday evenirg cls-ourse delivered at the Royal Institution, on 

 February 11, by Dr. J. H. Gladstone, F.R.S. 



bordering on the eastern half of the Mediterranean, and stretch- 

 ing eastwards to the Persian Gulf. The time, so far as Egypt is 

 concerned, includes the whole period from the first Pharaoh, 

 Menes, to the conquest of the country by Alexander the Great ; 

 ranging from about B.C. 4400 to B.C. 332. The chronology 

 employed throughout is that of Dr. Wallis Budge, of the British 

 Museum, who has adopted in the main that of Brugsch Bey. 

 This period of 4000 years appears to me reasonable, and errs, if 

 anything, on the side of moderation. Our knowledge of the 

 other nations does not extend to anything like so remote a 

 time. 



Egypt. 



If we take as our starling-point Seneferu's triumphal tablet in 

 Wady Maghara, in the Sinaitic peninsula, we see the king 

 flourishing his battle-axe over the head of his enemy. This 

 symbolises the conquest of the copper and turquoise mines of 

 that region, and implies, of course, their previous existence as a 

 source of wealth. In the hieroglyphic inscription above his 

 head there is not only the king's name spelt phonetically, but in 

 the royal titles are seen two ideographs which bear upon our 

 subject. One is the necklace or ornamental collar which is the 

 well-known symbol for gold ; and the other an axe, the head of 

 which resembles rather that of a copper than of a stone weapon. 

 These titles have no reference to the metals themselves, but 

 mean " Golden Horus" and " Beneficent Divinity." Before such 

 symbols could be used to express abstract ideas, they must have 

 been well known in their concrete form. The date assigned to 

 Seneferu is B.C. 3750 ; but the discoveries of the past year have 

 put in our possession the actual metals themselves, of a much 

 greater antiquity. M. de Morgan, late Director General of 

 Antiquities in Egypt, has explored an enormous royal tomb at 

 Nagada, the centre chamber of which contained the mummy of 

 the Pharaoh, with the cartouche of King. Menes, the reputed 

 first King of Egypt. If it be really his tomb, the probable date 

 will be B.C. 4400. What is interesting to us is that in two of 

 the chambers, among a multitude of articles made of ivory, 

 quartz, porphyry, wood, alabaster, tortoiseshell, mother-of-pearl, 

 obsidian, earthenware, corneliani, glass and cloth, there were 

 found some small pieces of metal, viz. two or three morsels of 

 gold, and a long bead of that metal of a somewhat crescent form, 

 together with some articles of copper — a kind of button, a bead, 

 and some fine wire. The button was analysed by M. Berthelot, 

 the well-known French chemist and politician, to whom we are 

 indebted for the examination of a very large number of ancient 

 metallic objects ; he states that it is nearly pure copper, without 

 arsenic or any other metal in notable proportion. 



These are the oldest metallic objects in the world to which 

 we can assign a probable date. But Prof. Flinders Petrie had 

 discovered, three years ago, also at Nagada, a great number of 

 objects of the same character, and among them a few small 

 copper implements. Some filings from a dagger, a celt, and a 

 little harpoon were analysed by me, and found to consist of 

 practically pure copper, without any trace of tin. The remains 

 of these filings are in the little bottles on the table. The age of 

 these tools must be comparable with that of the royal tomb, and 

 may possibly be even older. 



Of about the same period, and perhaps even earlier, area 

 number of tombs at and near Abydos, which have been explored 

 by M. Amelineau, bearing the names of kings unknown to 

 history, accompanied by hieroglyphics of archaic form. In 

 these have been found larger quantities of copper utensils, viz. 

 pots, hatchets, needles, chisels, &c., which M. Berthelot also 

 finds to be nearly pure metal, but some contain a little arsenic. 

 It would appear, therefore, that the Egyptians, at the very be- 

 ginning of the historic period were acquainted with the use of 

 gold and copper. Let us follow the history of these two metals, 

 beginning with gold, which, as it is generally found native, was 

 probably the first known to man. 



According to a letter just received by me from M. Berthelot, 

 all or nearly all the ancient gold that he has examined contains 

 more or less silver. This pale coloured gold is sometimes 

 termed electrum, and was found in great quantity in Asia Minor, 

 where the Pactolus and other streams ' ' rolled down their golden 

 sands." Gold is frequently represented in the Egyptian sculptures 

 and pictures ; for instance, in the very interesting scenes of social 

 life at Beni Hassan, circa B.C. 2400, illustrations of which I now 

 throw upon the screen, we see the goldsmiths making jewellery, 

 weighing out the metal, melting it in their little furnaces with 

 the aid of blowpipe and pincers, washing it, and working it 

 into the proper forms. In the picture of a bazaar at Thebes we 



NO. I4S6, VOL. 57] 



