March 22, 1877] 



NATURE 



455 



ASTRONOMICAL BIBLIOGRAPHIES 



PROF. HOLDEN, of the Observatory of Washington, 

 U.S., lately read to the Washington Philosophi- 

 cal Society a paper on *' Special Astronomical Biblio- 

 graphies," in which a careful comparison of one section 

 of the '• Reference Catalogue of Scientific Papers," by 

 Mr. E. B. Knobel, F.R.A.S. (lately mentioned in these 

 columns), was made with a MSS. catalogue on the same 

 subject (nebulae and clusters) which Prof. Holden had 

 compiled for his own use. Only one misprint was found 

 {op. cit.y p. 377, for Coinptes Rendus, vol. 28, p. 537, read 

 P' 573) 3-i^d only one omission of a highly important 

 paper, the " Siderum Nebulosorum Observationes, Hav- 

 niensis " of D'Arrest. The list of works given by Mr. 

 Knobel might be still further extended, but in its present 

 state it is very accurate and extremely useful. 



A list of bibliographical works available to the astrono- 

 mer for consultation is given, which we extract : — 



1. Weidler, " Bibliographia Astronomica," &c., 1755, 

 8vo. 



2. SCHEIBEL, " Astronomische Bibliographie," &c., 

 1789-98, 8vo. 



3. Lalande, " Bibliographie Astronomique," &c., 1803, 

 4to. 



4. Reuss, " Repertorium Commentationum," &c., vol. 

 V. 1804, 4to. 



5. Young, " Natural Philosophy," vol. ii. pp. 87-520, 

 2 vols., 1807, 4to. 



6. SOHNKE, "Bibliotheca Mathematica," &c., 1854, 

 8vo. 



7. [Schumacher], "Catalogue des Livres Composant 

 la Biblioth^que de I-eu," Prof. Schumacher, Part i, 1855, 

 8vo. 



8. Struve, " Catalogus Librorum in Bibl. Spec, Pul- 

 lovensis," 1858, 8vo. 



9. Royal Society, " Catalogue of Scientific Papers," 

 6 vols., 1867-72, 4to. 



10. Darboux et HouEL, Bulletin des Sciences, &c., 

 8vo. {serial). 



11. PoGGENDORF, " Biog.-Liter. Handworterbuch," 2 

 vols., 1863, 8vo. 



12. R. Wolf, SonnenfleckenLiterattir, Astr. Mil., 8vo, 

 {serial). 



13. R. Wolf, " Handbuch d. Mathematik," &c., 2 vols., 

 1872, 8vo. 



14. Carl, "Die Principien d. astr. Instrumenten- 

 kunde," 1863, 8vo., p. 161 [Literature of Micrometers]. 



15. Belgium Academy OF Sciences, "Bibliographie 

 Acad^mique," 1875, 8vo. 



16. St. Petersburg Academy of Sciences, " Ta- 

 bleau General," &c., Part i, 1874, 8vo. 



17. Engelmann, " Literatur d. astronomische Nach- 

 richten," &c., Bessel's Abhandlungen, 1876, 3 vols., 4to. 



18. Knobel, "Reference Catalogue of Astronomical 

 Papers and Researches." Mon. Not. R.A.S. 1876, Nov. 



19. Holden, " Index Catalogue of Works on Nebulae 

 and Clusters of Stars, 1876," MS. 



Almost any desired paper may be at once found by 

 means of these works, and Nos, 3, 4, 8, 9, il, 16, 17, and 

 18 are practically indispensable. 



MENDELEEF'S RESEARCHES 

 MARIOTTE'S LAW 



ON 



TN compliance with your request I hasten to make known, 



through your esteemed journal, to the scientific public of 



England, the results of my researches on the Boyle-Mariotte Law. 



Special reasons which I have explained in the Russian Journal 

 of Artillery (August, 1872), urged me to undertake new re- 

 searches on this law. They are briefly as follows : — 



I. It is impossible to admit in theory that under pressures 

 infinitely great gases can be condensed into a volume infinitely 

 small ; or, in other words, that it is possible to introduce into a 

 given volume an infinitely great mass of condensed gas. Although 

 infinitely great pressures be practically unrealisable they are per- 



fectly perceptible to the mind ; as to an infinite condensation of 

 matter it is quite inconceivable, otherwise we must admit the 

 existence of an atomic substance without volume. The experi- 

 ment of Cagniard-Latour developed and verified by MM. Wolf 

 Drion, Andrews, and myself lead us to an inevitable con- 

 clusion, viz., that at a certain known temperature all gases 

 and vapours can no longer be transformed under any pressure 

 into liquid, but remain in the gaseous state, endowed with elas- 

 ticity, but deprived of cohesion. At a lower temperiture the gas 

 may be transformed into liquid ; but at a higher temperature it 

 remains gas, whatever be the pressure. I gave to this tempera- 

 ture {Lieb. Ann., t. 119, p. ii) in i860 the name of "tempera- 

 ture of absolute ebullition ;" in 1872 Dr. Andrews gave it the 

 name of "critical point." 



Imagine a mass of gas at a temperature higher than this, and 

 suppose that this mass is subjected to pressures always increasing ; 

 if the Boyle-Mariotte Law is accurate the volume ought to diminish 

 in inverse proportion to the pressure. If we represent this 

 same mass of gas at a temperature a little less than that of abso- 

 lute ebullition, the gas transformed into liquid will cease to be 

 compressed as before, as the Boyle-Mariotte Law requires. 

 Consequently, there is no doubt that we ought to come to the 

 paradoxical conclusion : — A gas can be more compressed than a 

 liquid or solid. As there is reason to believe that oxygen at 

 the ordinary temperature is hotter than at its temperature of 

 absolute ebullition, the Boyle-Mariotte Law being admitted, 

 under a pressure of 2,000 atmospheres, we ought to find a specific 

 weight of oxygen greater than that of sulphuric acid, and the 

 pressure being 10,000 atmospheres, its density would reach that 

 of mercury. But it is impossible to admit this, judging from 

 what we know of the relation which subsists between the atomic 

 Weight of the elements and their density in the free state, as well 

 as in their combinations with other elements. It is sufficient to 

 indicate that a very great density is the peculiar property of 

 combinations, the elements of which are endowed with a con- 

 siderable atomic weight. Consequently, it cannot be admitted 

 that elements having so small an atomic weight as oxygen can be 

 condensed to any very considerable degree, no matter in what 

 state. We must then conclude, a priori, that under high pres- 

 sures the Boyle-Mariotte Law is inapplicable. 



2. The researches of Rumford, which date from last cen- 

 tury, relating to the density of the combustion gases of powder ; 

 also the researches of M. Natterer, on the compressibility of 

 gases like oxygen, the oxide of carbon, hydrogen, and air, made 

 in the years 1850 et seq., are completely in accordance with the 

 conclusions stated above, and show that under high pressure 

 gases are endowed with a positive compressibility analogous to 

 that of solid or liquid bodies. I mean by positive compres- 

 sibility that property by which bodies, in proportion to the 

 increase of pressure, diminish in volume less rapidly than 

 the pressures increases. In cases where the Boyle- Marioite 

 Law is found exact, the product pv oi the pressure p into the 



d{pv) 



volume V remains constant ; and 



dp 



o. When the com- 



pressibility is positive this product/ z^ increases together with the 



increase of the pressure, and consequently — ^f ' > o. 



dp 



3. At the same time MM. Despretz, Regnault, and many others, 

 have conclusively demonstrated that gases like carbonic and sul- 

 phuric acid, which are transformed into liquids under conside- 

 rable pressure, possess a negative compressibility, so that for thetn 

 d{pv) 



dp 



o. M. Regnault has found the same negative compres- 



sibility for air, nitrogen, and the oxide of carbon under pressures 

 higher than that of the atmosphere as far as thirty. It necessarily 

 follows that if the data of MM. Regnault and Natterer are correct, 

 the negative compressibility of air becomes under a certain pressure 

 above thirty atmospheres, equal to zero, and therefore positive. 



When ^P'^i = o, Mariotte's Law is verified. Consequently 



dp 

 there is a certain pressure above thirty atmospheres under which 

 Mariotte's Law is applicable ; under pressures below that point 

 the compressibility is negative ; under pressures above the same, 

 it becomes positive and remains so to the end. 



4. Although there is no doubt that the Boyle-Mariotte Law 

 is not rigorously applicable even under moderate pressures, yet 

 the prevailing doctrine, so rich in instruction on the nature of gases, 

 which deduces all their properties from the vis viva which ani- 

 mates their molecules, admits the supposition that in the rare- 

 faction of gases the distances between these molecules increase to 



