Millikan, R. A.

English

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SCIENCE T h e  Electron Theory of Matter. By 0.W. RICHARDSON, Wheatstone Professor of Physics at Kings College, London. Pp. vi ,+612. Cambridge Univ. Press. 1914. THIS is in many ways a very remarkable book. Its scope is broader than that of any book on Electron Theory which has yet ap- peared, and i t  has the unique merit of not fol- lowing even remotely the outline of J. J. Thomson's epoch-making work in this field. The author himself has exhibited within the past fifteen years, an unusual combination of theoretical and experimental fertility, and the present volume represents his digest, from the beginning, of the whole field of electromag-netic theory from both the theoretical and the experimental side. I t  exhibits profundity of soholarship, breadth of knowledge, enormous industry and a commendable fairness and rea- sonableness of temper. The first 216 pages contain mainly the author's own treatment of nearly all of the most important of the classical theorems of electromagnetism such as the various potential theorems and those growing out of the Max- well equations. From this point on is found a very exhaustive and original treatment of practically all of the newer developments of physics the scope of which can best be seen from the chapter headings. There are eighty pages on the electrodynamics of a moving charge, including a full discussion of the Abraham and Lorenz theorems; sixty pages on relativity; thirty-five on radiation and tem-perature with Wien's and Plancln's contribu-tions; forty on the theory of magnetism with a full review of Weiss' work; seventy-five pages on the electron theory of metallic conduction, thermo electromotive force, and thermoionics; thirty-five pages on "Types of Radiation" corpuscular and ethereal, including recent X-ray theory; thirty-five pages on spectroscopic phenomena; forty on the structure of the atom with Thomson rather overdone and Nicholson and Bohr somewhat slighted; and sixteen on gravitation. Altogether i t  is a book of large and perma- nent value and another testimony to the breadth and fecundity of British science. R. A. MILLIEAN RYERSON LABORATORY,PHYSICA  UNIVERSITYCHICAGOOF SPECIAL AXTICLES A SYSTEM O F  RECORDING TYPES OF MATING I N  EX-PERIMENTAL BREEDING OPERATIONS~ ALL Mendelian experimentation with bisex- ual forms implies a system of mating which in practical work is called line breeding. One starts any Mendelian experiment with two kinds of organisms which are crossed with each other to produce the F, generation. Then the F, individuals are either mated inter  se or back-crossed to the parent forms. The F, in-dividuals may be mated in a variety of ways inter  se and with the parents or grandparents. Many of those engaged in Mendelian work Diag~amI P generation B P R 8  X Houdan 9 J-Fl generation FIG' X FI9 from reciprocal cross J Fz generation Fzc? X BPR QI .L Fa generation Fs#M P generation Houdan c?X BPR Q /' Fl generation F I T Houdan 0 FSgeneration Fzg X F1Qfrom reciprocal cross IJ. F3 generation F3 0 N must have experienced the same difficulty that the writer has in recording experimental re-sults, namely, that of expressing adequately and completely, and at  the same time briefly and simply the general nature or type of the 1Papers from the Biological Laboratory of the Maine Agricultural Experiment Station, No. 88. SCIENCE [N. 8.VOL.XLII. NO.1081 pedigree by which particular individuals in the F, and F, generations are descended. To illustrate the meaning here let us consider the two individual fowls M and N produced as indicated in pedigree diagrams I. and 11. To describe in words how M or N was bred is a tedious piece of business. They are both breeding of each individual back to the orig- inal cross. The writer has wrestled for some time with this problem and tried out various schemes, such as the use of initial letters, fig- ures for years, etc. None of these has proved satisfactory in practise. It finally seemed clear that the only entirely satisfactory solu- TABLE I Matin,gs to  Produce F, F, individuals from a cross of the same two breeds of poultry, Barred Plymouth Rock and Houdan. Yet their breeding is very different. It is of the utmost importance in planning breeding experiments, especially when one comes to the matings of F, individuals, to have a clear picture in one's mind of the Number or Mating tion (to the writer at  least) would be one which was perfectly general. Such a general solution involves two things: first, a complete conspectus of all possible types of mating of the individuals of the P, F, and F, genera-tions inter se, both within and outside their own generations, and second, a simple, pre- BEPTEMBER 17, 19151 SCIENCE 385 ferably numerical, designation of each one of these possible types, each such designation to be of course unique and permanent. Table I. gives such a general solution of the problem of simply designating pedigree types, through the matings of F, to produce F,. Be-yond that it is not practical to go. A word should be said in explanation of the table. Letters denote individuals or groups of indi- viduals which are brothers and sisters. Solid lines, with circles in their course, connecting letters, denote rnatings of the kinds of indi- viduals indicated by the connected letters. Dotted lines lead from the mating to the kind of individual produced. Arrow heads indi-cate the direction of the mating, the arrow being supposed always to pass from the male to the female. Separate numbers are not given to reciprocal matings after the matings of the P generation to produce F,. To desig- nate separately reciprocal matings. after that point would greatly complicate the system without any significant gain from a practical point of view. I n  the later generations, re- ciprocals may be indicated if desired, by affix- ing a sub-figure 1 to the designation of the mating. The numbers within the circles are the des- ignations (or names) of the matings, and from the very nature of the case, these num- bers designate not alone the particular mating but also, in F, and later generations, the na- ture of the pedigree of each of the individuals entering that mating. This will be clear as we proceed. This table is to be read in the following manner: Individual Xc? is mated with Y? to produce F, individuals 2, and this mating is designated 0. Individual Y$ is mated with X? and produces F, individual P, and the mating is 1. The F, individuals, mated in all possible ways inter se and with the parents rY and Y, as indicated in matings designated 2 to 8 inclusive, produce seven kinds2 of F, in-dividuals, A to G. These seven sorts of F, individuals bred in all possible ways inter se and with their parents and grandparents pro- 2 "Kinds" referring here only to the manner in which the individuals have been bred. duce 56 sorts of F, individuals, as indicated in the lower half of Table I. As already noted, separate account of reciprocals is not taken. The use of the table may be indicated by some examples. Suppose one wishes to mate in an experiment the two birds called M and N in an earlier paragraph of this paper. He  will wish to indicate in some way in his notes the previous breeding history of each of these birds. If he does this verbally-and hitherto this appears to have been the only way of reaching such end-he must say of individ-ual N ,  for example, something like the fol- lowing: "This F, bird was produced by the mating of an F, male with an F, female pro- duced by mating a Barred Plymouth Rock male with a Houdan female. The F2 male was himself produced by the mating of an F,  male, out of the cross FIoudan male by Barred Rock female, on a pure Houdan female." Quite apart from the amount of space involved in such a setting forth of the facts, i t  is very difficult to form quiclily a clear mental picture of the bird's pedigree from this tedious verbal exposition. Suppose we are using the system of pedigree designation discussed in this paper we could then cover all the facts set forth above about bird N by merely writing in our notes "Bird N (58) BPR-Houdan series," and to describe completely the mating of 1W with N we have merely to write "F3GM (kZ)X F,?N (58) BPR-Houdan series." The figure 58 in the case of N means that she was produced from a mating of the type indicated in the table as E X  Z, and the des- DIAGRAM I1 Houdan 3 X BPR 9 (Y) (XI-/rC F I ~X Houdan 9 Fzc? d' 5 FI9 from reciprocal cross (El (58)  (2) J;N SCIENCE [N. S. VOL. XLII. No. 1081 ignation of such a mating is 58. This will be made clear by repeating the pedigree diagram of bird N ,  Diagram II., and adding to i t  the proper letters and mating designations from Table T. The simplicity of the scheme is obvious. No argument appears necessary as to its useful- ness in experimental breeding operations. The writer has found i t  extremely helpful and clarifying. A word should be added in regard to the system by which the numbers have been as-signed to the matings. It might at  first sight appear as though the arrangement were an entirely haphazard one. I t  is not. On the contrary the numbers will be found to con-form to the following general principles, which seem likely to be of aid in practical work, as tending to make i t  easy to recall from a number just what its particular pedigree looks like. 1. All even numbers refer to back-cross mat- ings. 2. All odd numbers refer to co-fraternal or intra-generation matings (not back-crosses). 3. Matings below 2 are of parental genera- tion individuals: between 2 and 8 inclusive are of F, individuals; niatings over 10 are of F, individuals. 4. Even numbers from 10 to 36 inclusive designate back-crosses of F, individuals with their grandparents, or individuals of the grandparental generation. 5. Even numbers from 40 up designate back-crosses of F, individuals on F, individ-uals. 6. In  the case of the odd numbers from 11 up i t  is, in a general way, true that the smaller the designating number of a mating the more closely related to each other are the two indi- viduals entering that mating likely to be. This principle of assigning the numbers could not be so precisely followed as the preceding five, but still is perhaps worth a little. I n  using this system in  one's notes or writ- ing it is of course essential to have the basic table always at  hand. If the plan should ap- peal to any number of experimental workers i t  would be a simple matter to have copies of Table I. printed on heavy cardboard to be used in breeding houses and pens, in the field and at  the desk. RAYMONDPEARL AGRTCULTURAL STATION,EXPERIMEN  ORONO,ME. THE CHEMICAL COMPOSITION O F  BORNITE SINCE the analyses of crystallized material from Cornwall by Plattner,l bornite has gen- crally been considered to be a cuprous sulfo- ferrite, Cu,FeS3(3Cu,S~Fe,S,). I n  1903 Har- ring-ton2 made a critical study of the published analyses, added several new analyses, and con- cluded that the chemical formula of bornite is Cu,FeS,(5Cu,S.FezS,). Recently I ' raus and Go1dsberry"ade an analysis of crystallized bornite from Bristol, Conn., which gave the formula Cu,J?e,S,(tiCu,S .Fe,S,), and also con- firmed Harrington's formula Cu,FeS,, of crys- t:~lliecd bornite from tire same locality. They concludc that bornite is of variable chemical composition, and in order to explain the facts they assume a morphotropic series of minerals ranging from chalcopyrite, CuFeS,, through barnhardtite, Cu,Fe,S,, and various bornites Cu,Fe,S,, Cu,Fe,S,, Cu,,Fe,S,, Cu,,Fe,S,, up to  CU,~F~,S,,,finally ending with chalcocite Cu,S, each member of the series differing from the one below it by the addition of one molecule of Cu,S. As a metallographic examination of the two analyzed bornites showed no foreign admix- ture, the work of Iiraus and Goldsberry fur- nishes, for the first time, proof that bornite Is variable in composition. I t  is believed, liow- ever, that there is a niose rational explanation of the variability in composition of bornite than the one advanced by Kraus and Colds- berry. The recorded analyses of bornite show a copper content varying from '7'7 to 55 per cent., and an iron content varying from 18 to 6 per cent. I n  Fig. 1I have plotted on the triangu- lar coordinate diagram of J. Willard Gibbs the available bornite analyses (59 in  number) given in Hintze's "Randbuch" and in the 1Pogg. Ann., 47, 351, 1839. 3 Amer. Jour. Sci., 16, 151, 1903. 3 Amer. Jour. Sci., 37, 539, 1914. 

The Electron Theory of Matter

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The Electron Theory of Matter

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