CHEMICAL NEWS, March 26, 1909 Change in Specific Gravity of Caustic Soda Solutions. 147 the time is traced, it will be seen that the activity decreases, One important fact will be noted here which might according to an exponential law, in such a way that the assist in an explanation. The titration with litrus is activity diminishes to the half value in twenty-two days. lower than with methyl-orange to begin with, but a point This is the number which expresses the period of the decay is reached ir ime where the two titrations come very of activity of uranium X. As for product B3, its activity close togethe The caustic soda used contained a conincreased in the ratio 33'5 = 2'37 in an interval of forty-solution conta ned 21° of hardness, due chiefly to bisiderable qua tity of alumina, and the water used for its I'41 carbonate of lime, being practically of the same composition as that supplied by the then Kent Water Works Co. On dilution always a certain quantity of alumina was four days. These results can be explained only by supposing that product B contained the immediate parent of uranium X besides uranium X. The separation process carried out with product B divided the two substances in unequal amounts between the three products B1, B2, and B3. Product B contains radio-uranium with an excess of uranium X, product B2 contains uranium X with a very small quantity of radio-uranium, product B3 contains radio uranium with a small quantity of uranium X. If the small amount of uranium X contained in product B is compared with the much larger quantity of it, which can be extracted from the original uranium solution, it will be seen that in these conditions radio-uranium is very difficult to separate from uranium. According to the above results this new substance must be classed between uranium and uranium X. Its presence in this position enables an explanation to be found for certain peculiarities which have been detected during the investigation of the uranium salts.-Comptes Rendus, 1909, cxlvii., 337. CHANGE IN THE SPECIFIC GRAVITY OF By CLAYTON BEADLE. WHEN Caustic soda solution of 60° T. made from certain kinds of 70 per cent caustic is diluted to a 16° Tw., rapidly mixed, and cooled to 60° F., the specific gravity is found to gradually increase; the writer first noticed this in August, 1889, when he made a number of observations. Such an observation as this must, it was thought, have been noticed by others, and consequently the writer did not attempt to publish the results. Moreover, the results were shown at the time to several chemists, who discredited them and could not offer any explanation. Since that time the writer has failed to discover any publications on the subject, and therefore ventures to think that these results may be of interest. found to rise to the surface as scum. If the dilution was made with distilled water, no separation of alumina took place. The following is an analysis of the incrustation formed on a galvanised-iron tank in which the 16' Tw. caustic This incrustation was formed soda solution was stored. as the result of the scum produced on dilution as above : When titrating in presence of methyl-orange, if alumina alumina is re-dissolved by the acid (vide Cross and Bevan, be present the neutral point is not reached until the Journ. Soc. Chem. Ind., April 30, 1889, No. 4, vol. viii.; also Robert T. Thompson, CHEMICAL NEWS, 1883 and 1884). With litmus, however, the final point is reached when the alumina is precipitated. The latter, however, is not very definite in presence of large quantities of dissolved alumina. The difference between the two titrations may be taken as a rough measure of the amount of alumina. Some 70 per cent caustic soda was at the time of these experiments dissolved in distilled water; a solution of the same having a specific gravity of 10317 contained 2.193 per cent Na2O by litmus titration and 1.868 per cent by methyl-orange titration. The solid caustic contained then an excessive quantity of alumina. On dissolving the caustic to a strong solution and diluting with the hard water some of the alumina is eliminated, and it appeared that the whole of it is eliminated on standing when the strength stood at 16° Tw. The subjoined table gives some further titrations and specific gravity determinations showing a marked increase in concentration on diluting and standing :- Time. January, 1905 1. 23rd, 10.30 a.m. 2. It was the duty of one of the workpeople in a large paper mill to reduce a 60° Tw. solution of caustic soda to 16° Tw. by running the stronger solution from a copper to a tank below containing hard water. Immediately on dilution and mixing, a sample was taken out and rapidly cooled to 60° F., and the strength taken with a Twaddell hydrometer. It was found that the solution some time after dilution always read considerably above 16° Tw. Consequently the writer took samples from a mixing, and found that the hydrometer actually rose in the liquid when kept at a constant temperature. The experiments were 4. repeated with a specific gravity bottle, when it was clearly demonstrated after filling the bottle that the liquid gradually underwent a contraction. The following titrations show this change : Strong Caustic Solution from (70 per cent) Caustic Soda freshly Diluted to 16° Tw. at 60° F. .. 3. 4. 22.30 5. 23rd, 3 p.m. 22.8 6. 23rd, 4 p.m. 19.65 19.65 19'0 1*08456 19.65 19.65 19'0 1*0847 I'1009 I'1157 I'1335 23.05 21.7 24'90 22.2 I. 24th, 2.30 p.m... 26.8 29.30 26.1 19.65 19'70 19:05 19'65 19'70 19.05 22.40 23.65 21.85 22.90 24.85 22.35 26.8 29.20 26.20 It may be possible that the sodium aluminate present in solution exhibits a lower specific gravity than the sodium carbonate present after the alumina has separated, but the increase in gravity would appear to be far too great to be accounted for on this basis; unfortunately no complete analysis of the caustic soda in question was made at the time, and the brand of caustic soda that showed this peculiarity is, we fear, no longer available, A NEW METHOD OF MATHEMATICALLY HARMONISING THE WEIGHTS OF THE NEWS Kremers, in 1852, "drew attention to the equivalents of several elements showing difference among themselves ELEMENTS, TOGETHER WITH A REVIEW OF approximately equal to 8, and to the fact that the equi KINDRED WORK, AND SOME OBSERVATIONS CONCERNING THE INERT GASES AND SATELLITES. By F. H. LORING. IN presenting a new method of harmonising the elements, I purpose at the outset to refresh the mind of the reader by reviewing briefly the previous work. It will be seen that many ideas, advanced from time to time, are to some extent recognisable in the method I have devised. Many workers in this interesting field have sought to arrange the elements in various ways, with the view to finding some plan or formula which would classify the elements according to their combining weights, or simply express their values by an equation. A considerable degree of success has been achieved, as will be seen from the following brief historic review of the subject. Probably the first attempt to classify the elements according to their weights was made by Richter (17621807), who thought that the combining weights of the bases formed an arithmetical series, whilst those of acids formed a geometrical series. Prout in 1815, and Meinecke in 1817, regarded the weights as whole numbers and multiples or polymers of hydrogen. Since then others have worked on the same idea, and comparatively recent developments have given some interesting results.* Döberiner (1817 and 1829) grouped a few elements in "triads." Gmelin, in his "Handbuch der Chemie" (1843), arranged the elements in two ascending rows which formed a broad faced V-figure. Over one limb he placed O, and over the other H, N being placed midway between the other two. F, Cl, Br, and I headed the O-limb, these standing side by side in horizontal alignment. S, Se, and Te formed the next row, and so on. Pettenkofer (1850) regarded the weights as whole numbers, and, by the addition or subtraction of integers, obtained a series. He thought that similar elements formed an arithmetical series resembling the organic radicals, and Dumas, with a like idea in mind, in 1851 formulated a law to the effect that those bodies having like characteristics will follow a sequence in weight and chemical properties, as instanced by Cl (gaseous), Br (liquid), and I (solid).t * Bernoulli (Zeit. Electrochem., 1907, xiii., 551) regards the atomic weights as mean values, the elements being a mixture of polymerides of hydrogen, just as the vapour of sulphur is regarded as a mixture of molecules S, S2, S4, &c. The author calculates by thermodynamic recurring formulæ the combinations thus possible. The weights need not be integral multiples of H, since the apparent atomic weight of an element may be a kinetic mean value. He gives weights calculated to the third decimal place. + This principle I have recently extended to include molecular groups as shown by the following table, the regularities of which must be regarded, however, as fortuitous: valents of some metals (Mg, Ca, Fe) are nearly products of 4 with an odd integer, whilst others (O, S, P, Se, &c.) are products of 4 with an even integer.' Gladstone, in 1853, published a paper “On the Relation between the Atomic Weights of Analogous Elements." He compares the atomic weights of elements with the molecular weights of organic radicals, and divides the elements into three broad groups :—(1) "Those having the same weight; (2) those whose weights form a geometrical series; and (3) those whose weights form an arithmetical series." Cooke, in 1854, arranged all the elements then known in six series, each of which he reduced to a general formula of this order :-8+ng; 4+ n8; 8+n6; 6+n5; 4+4; and 1+13. The first group included O, F, Cl, Br, and I. Lenssen, in 1857, arranged the elements in triads, and obtained twenty groups. Strecker, in 1859, called attention to the following series :-Cr 26:2, Mn 27.6, Fe 28, Ni 29, Co 30, Cu 317, and Zn 32.5. Lothar Meyer, in 1860, observed (1) "if the elements be arranged in order of their atomic weights, there is a regular and continuous change of valency as we pass from family to family; and (2) "that the successive differences of elements in the same column are at first, approximately, 16, except Be, then they increase to about 46, and, finally, approach a number ranging from 87 to go." De Chancourtois, in 1862, devised the "Telluric Helix," which is well known. The elements are arranged on a cylinder so as to trace a spiral. Supplementary helices are required to take all the elements. Newlands (1863-64) wrote as follows:-"If elements be arranged in the order of their equivalents, with a few slight transpositions, it will be observed that the elements belonging to the same group usually appear in the same horizontal line. It will be observed that the numbers of analogous elements generally differ by 7 or some multiple of 7." In other words, the members of the same group stand to each other in the same relation as the extremities of one or more octaves of music.† Mendeléeff, in 1869, first published his Periodic System. This was to some extent foreshadowed by Lothar Meyer, Newlands, Dumas, and others. The work is too well known to need description here. Mills, in 1884, sought to express the atomic weights by the equation At. wt. K-158*. K is practically the number of a series-15, 30, 45, &c.; x is an integer of variable magnitude according to the elements selected, while B=0.93727. He divided the elements into 16 groups. Reynolds, in 1886 (see CHEMICAL NEWS, 1886, liv., 1), described a geometrical method of illustrating the Periodic Law by a It will be seen that practically all the potential acid-forming bodies (in the sense of not possessing hydrogen) which yield monobasic acids at laboratory temperatures tend to exist as stable compounds having a molecular weight that is an approximate multiple of 23. Thorp and Hambly have confirmed the observation of Mallet that hydrofluoric acid is dibasic below 30°. Fluorine does not belong therefore to the series, nor should one expect it to be eligible, since the weight of Fa is not an approximate multiple of 23. Bodies that conform to this rule fall into periods (P) numbered 2, 3, 4, 5, &c. (W is the weight of the gaseous bodies in grms. per litre at o 760 mm. sea-level, lat. 45°, which is of the same order as P being consequent upon the law of Avagadro). This may be taken, notwithstanding the agreements, as an example of chance regularities. This I have quoted from Rudorff's "Periodic Classifications," &c. He reviews most of the work done prior to 1900, the date of publication of his book. Reference to papers not described therein will be given in the course of the article. I have made use of his abstracts, but the original papers should be consulted, as it is difficult to do justice to the work in a brief summary. + Rev. H. G. Wood, of Boston, Mass., in his book, "Ideal Metrology in Nature, Art, Religion, and History" (1908), arranges the elements on what he terms the "geometric scale of doubles." Beginning at 240 for middle C, he has to some extent harmonised the atomic weights by taking tenth parts of the following musical-scale numbers (vibrations) as multiples:-C 240, D 270, E 300, F 320, G 360, A 400, and B 450; For example, 1/10C=24, C=12, Mg=24 32, Ti=481; 1/10C=256, V=512; 1/10D=27, Al=271. All the elements are treated in the same manner, giving twelve groupings. The agreements are fairly close, but the elements are not arranged in any known chemical order. CHEMICAL NEWS, Mathematically Harmonising the Weights of the Elements. March 26, 1909 zigzag line, which he subsequently elaborated and described in his Presidential Address to the Chemical Society, March 26th, 1902 (see Journ. Chem. Soc., Part 1, vol. lxxxi.) In his final arrangement he spaced the elements on curves which represent major and minor chord vibrations (stationary waves). The inert gases fell on or near to Tchitchèrin, in 1888, working on the nodal points. atomic volumes, proposed the formula At. vol.at. wt. X (2—0'00535 × at. wt. × N). This N is an integer which for Li and Na = 8, K=4, Rb=3, and Cs-2. Crookes, in his Presidential Address to the Chemical Society, March 28th, 1888, described a method of classifying the elements in which he afterwards embodies the inert gases (see Proc. Roy. Soc., June 9, 1899). is a figure 8 in plan, but in perspective it is a single line so looped as to trace a succession of fig. 8's, one over the other. The elements are arranged on equally spaced vertical lines where they intersect the loops. Many elements having like characteristics fall under each other, i.e., in vertical alignment. Stoney, in 1888 (Phil. Mag., 1902, iv., 411), represented the atomic weights as volumes of concentric spheres which are shown on a plane by a system of concentric circles. By introducing equally spaced radial lines, the points of intersection taken progressively, say, in a clock-wise direction, formed a spiral which approximated to one that could be derived from logarithmic or elliptic formula. Like elements, except H and He, fall on the same radial lines. Carnelley (1890) gives the formula At. wt. = C(M+ √V). M is a term of an arithmetical series depending upon the group to which the element belongs, V is the number of the group, and C is a constant. Adkins, in 1892, builds up the different elements from the series, 7 Li, 9 Be, 11 B, and 12 C, by adding these to numbers: 7, 9, 16, 24, 56, 78, and 94. Rydberg (Zeit. Anorg. Chem., 1897, xiv., 66) shows that the elements from He to Fe approximate to whole numbers, the weights being expressed by the sum of two parts (N+D). Comstock gives a clearly expressed table of Rydberg's system (Fourn. Am. Chem. Soc., 1908, xxx., 683). This table I reproduce below with the 1909 weights. N is an integer and D is a fraction, generally positive, and less than unity. If M is the number of the element, then N is equal to 2M for elements of even valency, and 2M+1 for those of odd valency. The following table will make this clear : 149 J. Schmidt (Zeit. Anorg. Chem., 1902, xxxi., 146) cal culates the atomic weights of the elements by assigning thereto (except to hydrogen) chemically inactive portions a, and assumes that chemical attraction obeys the universal laws of attraction. b is the attractive portion. Monovalent atoms are represented by a+b, bivalent ones by a+b+b2, and so on. Certain assumptions are made, and the calculations are in fairly satisfactory accordance with weight determinations. A. Marshall points out some curious regularities that appear when the atomic weights are referred to other standards than those of O and H (Chem. Zeit., 1902, xxvi., 663, and CHEMICAL NEWS, 1902, lxxxvi., 88). For example, when those of Cl, Br, Ag, and I (German Committee weights taken at the time), are multiplied by 2.53868, whole numbers 90, 203, 274, and 322 are obtained. By dividing Li, NH4, Na, K, and Rb by 1'004, each division gives respectively 7, 18, 23, 39, and 85 exactly, except a small difference in the case of Na. The same factor gives practically whole numbers for Pb, Cd, V, Pt, Sn, Ca, and Al; the factor 1.0551 is given for the Zn-V series. The author connects these regularities with the phenomena of isomorphism. Vincent finds (Phil. Mag., 1902, iv., 103) "that if a list of all the atomic weights in ascending order of magnitude be taken, and the order in this list be called n, then the nth atomic weight, from n=3 to n = 60, is given by the equation W=(+2) 121." Iodine is least in agreement by a difference of +3.9. Hughes considers the elements as built up from corpuscles analogous in type to the radicals NH4, CN, CH, and NH (CHEMICAL NEWS, 1903, lxxxviii., 298). Calculations are given. Wetherell takes 4 and multiples of 4, and classifies the elements according to the Periodic System (CHEMICAL NEWS, 1904, xc., 260; see also vol. xc., p. 271). He regards the abnormal properties of beryllium (low specific heat, &c.) as due to the presence of a satellite. In the case of Be, the satellite would be relatively large. Te, he suggests, may have a a relatively small satellite, and account for the Te-I inversion in the Periodic Table. Minet (Comptes Rendus, 1907, cxliv., 428) assigns to the elements serial numbers, and, by adding six new elements curve, to the series, plots the atomic weights by a x=x1215. Two modifications of the same order are given. Delauney (Comptes Rendus, 1907, cxlv., 1279) finds curious whole-number relations, thus: C = 122, Zr = 332, Ce = 292, and Ti 12 ', 12 6 More examples of this kind are given. = 172 6 From the foregoing it will be observed that the methods employed may be classed as―(1) those involving a mathematical treatment without regard to any particular chemical order or classification; (2) those in which the parallel arrangement or gradation of the elements is accomplished, although the mathematical treatment is somewhat imperfect; and finally (3) those involving the calculation of the weights, some useful classification being arrived at at the same time. While the best general chemical classification of the elements may not accord with their mathematical or geometrical harmonisation, the two ideas are not necessarily opposed. The difficulties are certainly great. But the failure to bring the two methods into perfect accord does not imply that a purely mathematical treatment is not possible. Moreover, a mathematical treatment, if it accords with facts, may lead to new discoveries, and bring to notice other properties than those usually associated with the classification of the elements. It is with the view of showing a remarkable series of regularities of an apparently exact mathematical nature that the plan below given is suggested. This method is based upon two simple operations. The first is to arrange the elements in a regular series, that passes through a zero, according to the empirical equation,±(4P) + K = W; P is a number of an integral series, o, 1, 2, 3, and K is a constant of somewhat arbitrary selection which, Be (?) in the calculations here given is 31. This equation gives the value W, approximating to the true atomic weight by a plus or minus difference ranging from o to o9.* IO. B Na Fe Cu Br Co Sr As Si &c., H Li K V Mn Se Yt Ge Р Zn - Nb Ru II. 12. The second operation consists in projecting the dif ferences between the calculated and actual atomic weights horizontally along a line on which, by the above equation, the element is placed. Referring to the accompanying chart, it will be seen that the elements are first, as it were, hung on the rungs of a ladder, according to their nearness in weight to the values assigned to the rungs by the equation. The ladder passes through a zero, the rungs being four units apart. It should be here noted that, in order to avoid making the letterpress of the tabular part too wide, the names that fall on the same line are shifted to the nearest blank space, and dotted arrows are introduced to connect them with the lines on which they belong. The final allocation of the elements in the "difference" portion of the chart reveals some chemical regularities, although the true significance of the classification in this respect is not attempted as yet. The alkali metals, except rubidium, fall in the central part of the table, and if the table is folded down the centre on the O-line, so as to superpose the + and sides, many like elements are brought into approximate line. It is not my present object to attempt any chemical classification, and I do not believe that the system in its present form lends itself to a periodic arrangement worth considering. Gallium, lutecium, and neoytterbium do not fit into the series as they give differences greater than o'g. Moreover, their weights are not known accurately to the first decimal place. This may be said of a number of the heavy elements which are included. The chart may, of course, be extended to take radium and uranium. It is of importance to note that only those elements having certain numerical values fit into the series, and about the same number fall on the positive as on the negative side. The true zero of the system may be taken on the hydrogen line or a fraction of a unit below it. Those elements that fall on the o‘9 line (−) fit also on the o'9 line (+), and this suggests that such elements should easily change the sign of their valence. Carbon is an example in this respect. The most interesting part of the table is the elliptical curves which are drawn mechanically, and are symmetrically disposed with reference to the hydrogen line. They are all formed round the common foci (++), and spring from the 4-unit lines (where the latter intersect the +0.8 vertical line) on which the elements fall. The curves occur in groups of 9, and intersect practically all the elements. There are two such groups clearly defined. The third is doubtful, as the elements belonging to it would be of very large magnitude, and no accurate determinations are available for the purpose of establishing the curves. The regular manner in which the double curves intersect the elements will be seen from the table (see next column). In preparing this table, those elements not practically on the curves are moved to the nearest curve. The transpositions are very slight, considering the number of elements involved, and the fact that a number are not accurately known to the first decimal place. To make the Cr 182 Ba Cs Gd Pr Nd Ta table even more symmetrical, I should be moved to the curve No. 14 and Er to the vacant space on curve No. 16. The table predicts an unknown inert gas, designated by Y, which has been looked for.* The altered atomic weights of some of the inert gases are those kindly given to me by Sir William Ramsay, these being derived from new density determinations. Otherwise the table (chart) is in accord with the International Weights for this year. The prediction of Y has been arrived at by three more or less independent ways. In the first place, it will be noticed that a circle intersects He, A, and Ne exactly, and also Kr by a correction in the second decimal place. These gases, except He, are also intersected by the elliptical curves, and Xe is only a little out. Their position on the curves were noted to be thus:-A first, Kr second, Ne first, Xe second; therefore Y should be first, i.e., not preceded by an element, to preserve the regularity. Referring to the table above, it will be seen that Y should be on the curve with Sa, which is the second element. Assuming that Kr, Xe, and Y might also be intersected by a circle of the same radius as the one that intersects the others, by a trial method I found the position of Y, which coincides with the elliptical curve where it intersects a 4-unit line. The correction of the weights of the inert gases by the "three " intersections gives the following : Nitrogen and beryllium are the only elements which do not fit into the system. The difference between the observed weight of N and the calculated value for the Be falls away from any series is of the order of II. Wetherell (see citation above) has sugprobable curve. gested that Be and Te carry satellites, which he suggests would account for the abnormal specific heat of the former and the wrong position of Te with respect to I in the I suggest that Be, N, and I carry periodic classification. a satellite each, which by trial I find to be about 0.2684. Subtracting this figure from N (14'0064) gives 13.7380, which value falls on the first circle. Similarly, assuming Be to be 90874 instead of 9.1, and subtracting o 2684, gives 8.8190, which places Be, minus its satellite, on the first * Ramsay (Roy. Soc. Proc., Ser. A, Aug. 27, 1908, lxxxi., pp. 178 180) says the Periodic Table shows gaps for two or three inert gases of higher atomic weight than Xe, and an exhaustive search has failed to indicate any new gas, which he says may be due to its instability. like the emanations of radium, thorium, and actinium. Their weights should be about 172, 216, and 260. In the same Proceedings, pp. 195209, Moore reports that he has found no traces of a new constituent of the atmosphere upon careful search, and says that if a new element exists, it must, in all probability, be in less quantities than I in 2,560,000,000 parts of air. |