Oct. 3T, 1872] 



NATURE 



545 



constitute a quorum : it will choose a president and secrclary, 

 and will meet as often as it deems necessary, but at least 

 once a year. (/'.) The Committee will direct and superintend 

 the execution of the decisions of the International Commission, 

 in reference to the comparison of the new metric prototypes with 

 each other, as well as the construction of balances and other 

 auxiliary apparatus necessary for these comparisons, [c.) The 

 Permanent Committee will ]5erform the work indicated in (/') 

 with all appropriate means which may be at its disposal ; it will 

 meet for the performance of its task at the International Bureau 

 of Weights and Measures, the establishment of which will be 

 recommended to the nations interested. (</. ) When the new 

 prototypes will be constructed and compared, the Permanent 

 Committee will give a report of its work to the International 

 Ccimmission, which will sanction the prototypes before distribu- 

 ting them to the different countries. 



36. The Commission suggests to Governments interested how 

 great would be the utility of founding at Paris an International In- 

 stitution of Weights and Measures, upon the following bases ; — 

 1st. The establishment would be international and declared 

 neutral. 2nd. Its seat will be at Paris. 3rd. It would be founded 

 and supported at the common cost of all the countries which 

 adhere to the treaty that might be made between the interested 

 states for the creation of the establishment. 4th. The establish- 

 ment will depend upon the International Metric Commission, 

 and will be placed under the superintendence of the Permanent 

 Committee, who will choose the director. 5th. The Interna- 

 tional Bureau would serve the following purposes : — (17.) It will 

 lie at the disposal of the Permanent Committee for the compari- 

 sons which will serve as a basis for the verification of the new 

 prototypes with which the Committee is charged. (/'. ) The 

 preservation of the international prototypes, in accordance with 

 tlie directions laid down by the International Commission, (c.) 

 The periodical comparison of the international prototypes with 

 the national standards and with the tests, as well as that of the 

 standard thermometers, according to the rules laid down by the 

 Commission. (1/.) The construction and verification of the 

 standards which other countries may require in future, (e.) The 

 comparison of the new metric prototypes with the other funda- 

 mental standards employed in the different countries and in 

 science. (A) The comparison of standards and scales which 

 may be sent for its verification, either by Governments or by 

 scientific societies, or even by mechanicians and servants, [g. ) 

 The Bureau would execute all the works which the Commission 

 or its Permanent Committee would require of it in the interest 

 of metrology and the propagation of the metric system. 



37. The Bureau of the Commission is required to apply to the 

 French Government, and request it to be good enough to com- 

 municate diplomatically the views of the Commission concerning 

 the foundation of an International Bureau of Weightsand Measures 

 to the Governments of all the countries represented in the Com- 

 mission, and to invite these Governments to conclude a treaty 

 to create harmoniously, and as soon as possible, such an Inter- 

 national Bureau upon the bases proposed by the Commission. 



IV. Conctriiing the iiuans of Pri'scrring the Standards and the 

 Guarantee of their Jiwariability 



38. The Commission is ol opinion that the International 

 .Standard ought to be accompanied by four identical measures, 

 maintained at a temperature as invariable as possible ; another 

 identical measure ought to be preserved, for the sake of experi- 

 ment, at an invariable temperature in vacuo ; it would take 

 means to establish tests in quart/: and beryl, to be compared at 

 any time with the complete measure, in whole or by portions. 

 (The other means are reserved.) 



39. The Commission thinks that in the interest of geodesy the 

 French Government should cause to be re-measured, at a con- 

 \ -r.ient time, one of the new French bases. 



All these resolutions were made by the Commission most 

 harmoniously, and in a spirit of complete confraternity ; all the 

 votes were nearly unanimous. 



BIRTH OF CHEMISTRY 



III. 



Practical Chemistry of the Ancients.— Metallurgy : "gold, silver, 



electrum, eoppa-, bronze, tin. 

 T \ the preceding articles we have discussed such theories of the 

 ancients as involve the conception of change of matter (notably 

 the assumed transmutation of the elements), and 'which hence 



concern the early history of chemistry. Having done with theory, 

 we have now to inquire to what extent the ancients were .ac- 

 quainted with practical chemistry, what metals or other elements 

 were known to them, and what processes dependent upon chemi- 

 cal action. We do not, of course, use the term "practical 

 chemistry" strictly in its present sense, because chemistry as a 

 science was altOL ether unknown to the ancients. .Some have 

 indeed endeavoured to prove that the Egyptians must have been 

 acquainted with the science, from the skill with which they used 

 various metallic oxides for colouring glass ; but we have no proof 

 of this. Neither Herodotus, nor Pliny, nor Vitruvius, indicates 

 any knowledge of chemistry as a science among either ligyptians, 

 Greeks, or Romans. Pliny, in his celebrated "Natural History," 

 has laboriously amassed all the practical science and pseudo- 

 science which the ancients possessed, and we find no mention of 

 either chemistry or alchemy. At the same time it is impossible 

 that the Egyptians and Sidonians can have attained their mar- 

 vellous skill in the manufacture and colouring of glass, and in 

 the extraction and working of metals, without the acquirement 

 of a considerable amount of knowledge of the properties of 

 matter, and of certain chemical changes. But this knowledge 

 could never be worked up into a comprehensive system ; it resulted 

 from the labour of artizans, and the gulf between the philosopher 

 and the manipulator was both wide and deep. There could be 

 no union of practice .and theory. Between Herakleitos with his 

 theory that fire is the primal element, the actuating force of the 

 Universe, and the man who wrought metals never so deftly, who 

 applied fire to the use and service of mankind, there was no sym- 

 pathy, no reciprocal transference of ideas. To reason concern- 

 ing the properties of matter with one's eyes shut was all very 

 well, but to expermient with matter, to endeavour to determine 

 the cause of such and such a change by experiment, was utterly 

 unworthy of a philosopher. Anaxagoras is said to have made 

 an experiment to prove that there is no vacuum. Aristotle 

 found that a bladder of air weighed in air weighed more than 

 the empty bladder (which, if the experiment be properly made, 

 is by no n>eans the case), and hence concluded tliat the air has 

 weight. But these are solitary exceptions ; the w.ay to study 

 Nature, if she is to be studied at all, is, they maintained, to apply 

 the pure, unaided intellect to the study, and to keep mind and 

 matter as distinct as possible. From all this it resulted that your 

 workers in metals and in curious arts, your makers of glass and 

 pigments, kept their knowledge of matter to themselves, as secrets 

 to be handed down from father to son. 



Seven metals were known to the ancients, viz., gold, silver, 

 copper, tin, iron, lead, and mercury. The first six are mentioned 

 by 1 lomer, and appear to have been known from remote antiquity, 

 while mercury was not known till a later date ; it was, however, 

 common in the first century u.c. The Greek word ixeraWov, 

 whence inetalliiin and metal, signifies a mine, hence it was applied 

 to anything found in mines, notably metals ; ixtTaWtv is connected 

 with iCieraAA '«, " to search for diligently." 



Gold has been valued from the earliest ages, on ac- 

 count of the peculiarity o£ its colour, its lustre, and its 

 unalterability in air. The metal is invariably found in the 

 native state, that is, uncomliined with other substances, hence no 

 metallurgical operation is necessary for its extraction. It is very 

 often met with in surfacedeposits, and in early times wasundoubtedly 

 far more common in alluvium and the beds of rivers than now. 

 It would thus be easily extracted by washing, and the grains 

 ccHdd readily be fused together into a mass. Gold mines formerly 

 existed in Ethiopia, in which the gold was found in a matrix of 

 quartz, like much of the Australian gold of the present day. 

 These mines were worked by the Egyptians, who employed l.irge 

 gangs of slaves for the purpose. The quartz was crushed, and 

 the gold obtained from it by washing. We find representations 

 of gold washings, and the subsequent fusion of the metal, on 

 Egyptian tombs, at least as early as 2500 ii.c, that is to say, 

 about the.time of Joseph m Hebrew history. The woodcut (Fig. i) 

 on the following page is given by Sir Gardner Wilkinson, and is 

 taken from a tomb at Beni Hassan : it represents gold washing, 

 and the fusion and weighing of the metal. 



It is obvious that the process is only indicated, and not accu- 

 rately or minutely portrayed. Another form of furnace is 

 depicted below (Fig. 2), and a blowpipe somewhat different from 

 that shown in Fig. i. Theraised portion of the furnace is doubtless 

 for the purpose of concentrating the heat upon the crucible, on 

 the principle of the reverberatory furnace. 



Gold once obtained was soon made into ornaments ; very fine 

 gold wire was used Ijy the Egyptians for embroidery 3,300 years 

 ago. Many of the tgyptian and Etruscan gold ornaments are 



