SCIENCE. 



325 



ed that the corresponding oxyphthalic acid has the follow- 

 ing constitution. 



OH 



-COOH 



-COOH 



Nilrophthalic acid, melting at 165 , has the second (II) 

 formula, while the one melting at 212°, has the first (I) 

 formula. As stated above, these are both produced from 

 nitronaphthaline, which is itself an a compound, and so 

 it is demonstrated that the a position is the one next to 

 the two common carbon atoms. The hydrogen atoms in 

 naphthaline are combined in groups of four, each of which 

 is equivalent ; this follows naturally from the observed 

 facts in benzols. 



Atterberg, in his masterly researches on the chlo- 

 rinated naphthalines, found that in naphthaline, the 

 four a positions are of equal value without any reference 

 to the benzol formula. According to de Koninck, Mar- 

 quardt and Atterberg, nitronaphthaline may be con- 

 verted into a monochloronaphthaline. Therefore, in 

 these compounds, the nitro and chloro groups hold the 

 same position. The monochloronaphthaline may, how- 

 ever, be converted into a nitro compound and that into a 

 /3 dichloronaphthaline. Nitronaphthaline may be con- 

 verted into two different dinitronaphthalines, and those 

 into two different dichlornaphthalines 7 and 5. Hence 

 all three dichlornaphthalines /?, y, $, contain a chlorine 

 atom in the position of the nitro group of the nitronaph- 

 thalines. The three remaining chlorine atoms of the 

 three compounds must take different positions with refer- 

 ence to the first, since otherwise the three compounds 

 could not be different. All of the chlorine atoms of these 

 compounds possess an a position, consequently the naph- 

 thaline molecule must possess four a positions of equal 

 value. 



DETERMINATION OF THE CONSTITUTION OF THE 

 NAPHTHALINE DERIVATIVES. 



The constitution of naphthaline derivatives is ascer- 

 tained by converting them by a simple reaction into 

 another of known position. The nitro derivatives may, 

 for instance, be converted into the chlorine or bro- 

 mine derivatives by the chloride or bromide of phospho- 

 rus, and then by reduction into the amido derivatives. 

 These latter may, by means of their diazo-compounds, be 

 converted into phenols, chlorine, bromine (and perhaps 

 iodine) derivatives, and by means of formic acid into ni- 

 triles, and consequently into carbon acids. The bromine 

 derivatives produce, with ethyl and methyl iodide, ethyl 

 and methyl compounds, and with chlorcarbonic acid 

 ether carbon aoids are produced. The sulpho-acids give 

 with potassium cyanide, cyanates. With penta chloride 

 and bromide of phosphorus, chlorine and bromine de- 

 rivatives are obtained with sodium formate, carbon 

 acids ; and with sodium at a high temperature phenols 

 are formed. On the other hand the oxidation often shows 

 whether the substituting groups are in the same ring, or 

 are divided among both ; in the first case phthalic acid is 

 formed, and in the second substitution products of phtha- 

 lic acid are formed. 



CONSTITUTION OF THE NAPHTHALINE DERIVATIVES. 



The mono substitution products exist in but two mod- 

 ifications, and it is easy, therefore, to determine their 

 constitution. When in the bisubstitution products, the 

 two substituting groups are equal, ten different isomeric 

 compounds are obtained. If, however, they are unequal, 

 the number is increased to fourteen. The constitution of 

 a given number of the same is exactly known, while with 

 others it is only known that the substituting groups are 

 contained in the same or in two different rings, that they 

 possess an a or a j3 position, or a similar position. 



In the case of the higher substituted naphthaline de- 

 rivatives, the number of possible isomers is considerably 

 increased, especially when the groups are unequal. When, 

 however, the groups are equal, fourteen tri-derivatives, 

 twenty-two tetra-derivatives, fourteen penta-derivaties, 

 ten hexa, two hepta, and a single octo-derivative, in 

 which all the hydrogen has been replaced, are obtained. 

 There are, for example, seventy-five possible chlorine 

 naphthalines ; of these, however, only twenty-four have 

 been prepared. In order to simplify the nomenclature of 

 these numerous compounds, we will distiuguish the two 

 from each other by designating the same position in each 

 ing, as a 1 , a'\ (3\ and /3 2 . 



P 



ffl 



When a compound contains both of its substituting 

 groups in the same ring, we will combine the latter after 

 John's method, that is, by a simple line, as lor example, 

 a,-/? 1 , a'-/3 2 , a'-a 8 , etc. When, however, the groups are 

 divided between the two rings, then they are combined by 

 double lines, thus: a^=a\ a { =f3\ a 1 =p 2 , etc. The same 

 method of lettering may be used in the higher substituted 

 compounds; thus the compounds a 1 — /3 1 — a 2 , a 1 — /3 2 — a 2 , 

 a l —(i i —(i-—a 2 , have their groups in the same ring. The 

 compounds a 1 — a^zza 1 , a 1 — a 2 =/3', a}=a} — a 2 , a 1 — a 2 =a'— /i 1 , 

 have their groups divided between the two rings. We 

 have placed together, in a series of tables, the most im- 

 portant derivatives of naphthaline. In these tables will 

 be found their constitution as far as it is known ; some 

 characteristic properties, as their melting point, boiling 

 point, their formation, conversion, and, as complete as 

 possible, a list of the literature. 



It is to be hoped that the many vacancies which 

 appear among these tables may soon be filled. 



Last of all we would observe that the terms «, /?, y, (5, 

 etc., which we have chosen to represent the naphthaline 

 derivatives have no connection with their constitution 

 with the single exception of the mono derivative. They 

 have been given to the different isomers only in chrono- 

 logical order, and they do not correspond by any means 

 as far as position is concerned to the different a, (3, etc., 

 derivatives. This fact is unfortunate, because it may 

 cause confusion. We believe, however, that at present 

 no change should be made in names originally chosen by 

 the discoverers. When the constitution of the napthaline 

 derivatives is better known, a rational nomenclature ac- 

 cording to the above principals will naturally be adopted. 

 Thus for instance the present ft, y and f dichlornaph- 

 thalines will be designated as a 1 — a 2 , a 1 =a 2 and a'=«' di- 

 chlornaphthaline,the a and f5 trichlornaphthaline as a 1 — /3 1 — 

 /3 2 and «' — u 2 =a\ trichlornaphthaline, the a and (i chloro- 

 dinitronaphthahnes as a 1 — a^a 1 and a 1 — at^a 1 chloro- 

 dimitronaphthalines, and in a similar manner for all 

 other compounds by which their constitution will be im- 

 mediate!) recognized. 



NATIONAL ACADEMY OF SCIENCES. 



The abstracts of the papers read before the recent 

 meeting at New York were, in all cases, either corrected 

 or rewritten by the authors, and we are under obligation 

 to Professors James Hall, Wolcott Gibbs, E. D. Cope, 

 S. P. Langley, Henry Morton, Elias Loomis, B. Silliman, 

 O. N. Rood, T. Sterry Hunt, Henry Draper, for their 

 assistance in presenting correct reports. 



The addresses of Professor Alexander Agassiz and 

 Lieut. Shawatka were delivered viva voce, and we made 

 use of the stenographic notes made for the New York 



