CHEMISTRY. 



of all the raining rights in the country and cer- 

 tain limited grazing and timber rights. A com- 

 pany was formed at Cape Town to take over 

 this' concession, which was granted in August, 



1889, and announced to the public in January, 



1890. The regions of the upper Zambesi lying 

 north of Ngamiland were acknowledged in the 

 Anglo-Portuguese agreement to belong, on the 

 Hinterland principle, to Portuguese West Africa. 



CHEMISTRY. Chemical Theory. One of 

 the most important recent papers in the depart- 

 ment of chemical theory was the address of Vic- 

 tor Meyer at the meeting of the Association of 

 German Naturalists and Physicians for 1889, on 

 "The Chemical Problems of To-day." After 

 reviewing what had been accomplished in chem- 

 istry up to the present time, the author ad- 

 mitted that the science has not yet reached 

 mathematical completeness, and proceeded to 

 point out the questions now in sight of which 

 further investigation is needed. Most promi- 

 nent of these stand two fundamental problems 

 that must be solved before we can arrive at a 

 mathematico-physical treatment of chemical phe- 

 nomena in general. They are, What is chemical 

 affinity? What is valency? The doctrine of 

 structure, developed by a number of chemists 

 from Hoffmann to Kekule, has been further ad- 

 vanced by the stereometric researches of Van't 

 Hoff, who has been able to map out with great 

 probability the arrangement in space of the atoms 

 of the molecule. The linking together of atoms 

 is found by other researches to be dependent on 

 electrical conditions, or to be determined by the 

 presence of two opposite electric poles which rest 

 at the ends of a very short line. Such a system 

 is called a dipole, and the attachment of two val- 

 encies to each other consists in the attraction of 

 their opposed poles. Other facts relative to the 

 positions, dimensions, and rotations of the val- 

 encies furnish a hypothesis which opens the way 

 to an understanding of the most important prop- 

 erties of that attribute. The doctrine of sub- 

 stitution has likewise experienced a peculiar en- 

 largement. Dumas first showed that the prop- 

 erties of organic compounds are generally little 

 changed when the hydrogen of the same is re- 

 placed by univalent elements or groups. Later 

 experiments have shown that even much more 

 radical changes in the composition do not mate- 

 rially influence the properties of the substance. 

 One of the most far-reaching discoveries of our 

 epoch is that of the natural system of the chem- 

 ical elements, or the principle that their prop- 

 erties are functions of their atomic weights, with 

 which the names of Newlands, Mendel eeff, and 

 Lothar Meyer are associated. The natural sys- 

 tem has imposed on us a problem of great sig- 

 nificance in the new determination of the atomic 

 weights, the numerical values of which are now 

 of increased interest. Numerous other problems 

 are presented by the system. We do not yet dis- 

 cern the cause of the inner nexus of the elements 

 as the system offers it. The less studied ele- 

 ments need to be brought into the system. New 

 elements indicated by it remain to be discovered. 

 We know to-day about seventy elements ; Men- 

 deleeff 's table has places for exactly one hundred. 

 Other problems calling for continued study lie in 

 the field of dissociation and include the possi- 

 bility of further decomposing any of our present 



supposed elements; the nature of solution, in 

 which new methods are found for the determi- 

 nation of molecular weights: and in thermo- 

 chemical questions. In organic chemistry, the 

 discoveries that have been made in the produc- 

 tion of valuable colors, aromatic substances and 

 drugs from coal-tar products, and successful ex- 

 periments in synthesis invite to further research. 

 Many amorphous substances still need to be 

 studied and analyzed, and new methods are 

 wanted for recognizing the individuality of such 

 substances. The farmer has been occupied from 

 time immemorial in preparing starch from car- 

 bonic dioxide and water, and chemistry is not 

 likely to offer any improvement on his process. 

 " But we may reasonably hope that chemistry 

 will teach us to make the fiber of wood a source 

 of human food " ; and " the increase of albumen 

 in plants, according to a plan, together with the 

 production of starch out of cellulose this would 

 in reality signify the abolition of the bread ques- 

 tion." 



An attempt has been made by F. W. Clarke to 

 estimate the relative abundance of the chemical 

 elements on the earth, including the air and the 

 ocean. For the data of his calculations, the 

 author has taken the analyses of the ocean de- 

 scribed by Dittmar in the " Reports of the Chal- 

 lenger Expedition " and the mean of 880 analyses 

 of rocks made by geologists in the United States 

 and Europe. These analyses give fair bases for 

 the computation of the relative proportions of 

 nine of the chief rock-forming elements. The 

 proportions of the others are less easily comput- 

 able, but special examinations of the analyses 

 make fair estimates possible, till the number of 

 calculable elements is carried up to nineteen ; 

 while the fifty left unaccounted for can hardly 

 aggregate altogether more than 1 per cent, of 

 the whole. From the table embodying the re- 

 sults of the calculations, the nine elements first 

 mentioned appear to constitute 98 per cent, of 

 all known terrestrial matter. They are : Oxygen, 

 49-98 per cent. ; silicon, 25-30 per cent. ; alumi- 

 num, 7'26 per cent. ; iron, 5-08 per cent. ; calcium, 

 3-51 per cent. ; magnesium, 2-50 per cent ; so- 

 dium, 2'28 per cent. ; potassium, 2*23 per cent. ; 

 and hydrogen, 0'94 per cent. The rest of the 

 nineteen elements are, in the order of their 

 abundance, titanium, carbon, chlorine, bromine, 

 phosphorus, manganese, sulphur, barium, nitro- 

 gen, and chromium. / 



Another attempt to explain the genesis of the 

 elements has been made by Mr. H. M. Vernon. 

 Supposing .the various elements to have been 

 formed during the process of the cooling of 

 matter by the association, first, of atoms of the 

 primordial matter among themselves, and then 

 of the resultant molecules with other primordial 

 atoms, kinds of matter or elements would be 

 formed more or less stable as to heat. At- 

 tempts to resolve such elements into their com- 

 ponents have so far failed because of the impos- 

 sibility of applying a sufficient degree of heat ; 

 but the fractionation experiments of Mr. William 

 Crookes and his " meta-elements " indicate that 

 these efforts are in the right direction. We look 

 to the sun to learn if disintegration of some of 

 the elements may not have been effected there, 

 at temperatures higher than any that can be ob- 

 tained on the earth. By spectroscopic analysis 



