'.fS 



NATURE 



[November 28, 1912 



The November issue of The Journal of Physical 

 Chcmislry contains papers by Mr. F. F. Fitzgerald on 

 llie electrical conductance of solutions in methylamine 

 and ethylamine and on the fluidity of ammonia, methyl- 

 amine, and sulphur dioxide, and the fluidity of certain 

 .solutions in these solvents. The former paper is re- 

 markable for a series of curves of molecular conduct- 

 ance of potassium iodide and silver nitrate. in methyl- 

 amine, in which a maximum is reached in concen- 

 trated solutions, in addition to the usual maximum at 

 infinite dilution ; in the cases now recorded the two 

 maxima are separated by a very strongly developed 

 minimum, which is most pronounced at the higher 

 temperatures. In ethylamine, a weaker ionising sol- 

 vent, the maxima in concentrated solutions are equally 

 pronounced, but the dilutions studied were not suffi- 

 cient to reach the minimum, and the final maximum 

 representing; complete ionisation was quite inaccessible. 

 These phenomena, which have been noted in several 

 instances by Franklin and others, and probably depend 

 on the autolytic conductivity of the salt in the more 

 concentrated solutions, are of considerable importance 

 in studying the theory of electrolytic conductivity. 



.\ COPY has reached us of the current number of 

 Merck's "Annual Report" upon recent advances in 

 pharmaceutical chemistry and therapeutics. As 

 former readers of the report will know, it emanates 

 from the well-known Darmstadt chemical works, and 

 aims at giving in an impartial manner new informa- 

 tion likely to be of use to medical men and pharma- 

 cists. Only those drugs are discussed which have 

 been introduced into therapeutics as a result of scien- 

 tific research ; " secret remedies " and scientifically 

 questionable preparations are excluded so far as pos- 

 sible. The special articles upon groups of drugs, 

 which are a feature of the work, are this year devoted 

 to the glycerophosphates and to the digitalis glucosides 

 and allied drugs. The first article is a good summary 

 of our present knowledge ,of the salts of glycero- 

 phosphoric acid and their medical applications. In 

 the second, the history, chemistry, and pharmacology 

 of the complicated digitalin group are treated at con- 

 siderable length, the article running to a hundred 

 pages, and including what appears to be an exhaustive 

 bibliography of the subject. Of the general sections, 

 those on the cacodylates, salvarsan, sera and antigens, 

 the hypnotic action of adalin, bromural, and veronal, 

 and on the use of sterilised kaolin in the treatment of 

 dysentery and cholera, are specially worthy of note. 

 The report is quite up to the standard of former 

 issues, and as a record of new therapeutic prepara- 

 tions and of new uses for drugs already known, will 

 be found very useful. 



In Engineering for November 22 Prof. .-\. H. Gib- 

 son, of University College, Dundee, gives a brief sum- 

 marv of the results of experimental work on the resist- 

 ance to the flow of air through pipes. From experi- 

 ments made by Dr. J. H. Grindley and himself, it 

 annears that anv formula of the usual form — 



only applies if the coefficient / is varied, not only with 

 XO. 2248, VOL. 90] 



the physical condition of the interior surface of the 

 pipe, but with its diameter, \yith the mean velocity of 

 flow, with the mean pressure, and with the tempera- 

 ture of the air. Prof. Gibson proposes a new formula 

 which he has tested against a large number of results 

 by different experimenters. The practical form of the 

 formula for cast- or^ wrought-iron pipes laid under 

 normal Qonditions as regards jointing, &x., and for 

 air at a temperature of about 65° F., is — 



r;)> = o 00000125/ ---_ lb. per sq. m. 



Here d and I are the pipe diameter and length re- 

 spectively in feet, /> is the mean absolute pressure of 

 the air in the pipe in lb. per sq. in., and v is the 

 velocity in feet per second; n has values as fol- 

 lows : — 



Diameter, inches 



183 rSi 179 178 177 



The formula gives the drop in pressure with a high 

 degree of accuracy. It may be rendered applicable to 

 other temperatures by introduction of a coefficient K, 

 the value of which depends on the values of n and of 

 the temperature ; a table of values of K is given from 

 which it appears that at 32° F. K is o'gSo when n is 

 i"28, and is 1052 when n is 1S5. .\t 180° F. K is 

 i'o6i when n is \'2%, and is o'865 when n is i'85. K 

 is unitv for all values of n at 6;° F. 



OUR ASTRONOMICAL COLUMN. 



Astronomical Occurrences for December : — 

 Dec. 2. iSh. 55m. Mercury in conjunction with 

 Jupiter (Mercury 0° 35' S.j. 



7. loh. 12m. Mars in conjunction with the 



Moon (Mars 4° 2' N.). 



8. 7h. 7m. Mercury in conjunction with the 



Moon (Mercury 6° 11' N.). 

 ,, iih. om. Mercury in inferior conjunction 



with the Sun. 

 ,, 2oh. 55m. Jupiter in conjunction with the 



Moon (Jupiter 5° 7' N.). 

 II. 1411. 46m. Venus in conjunction with the 



Moon (Venus 2° 42' N.). 

 ,, iSh. 17m. Uranus in conjunction with the 



Moon (Uranus 4° 15' N.). 

 13. 3h. 38m. Venus in conjunction with 



Uranus (Venus 1° 36' S.). 

 18. 8h. om. Jupiter in conjunction with the 

 Sun. 

 ,, (}h. om. Mercury stationary. 

 21. loh. 29m. Saturn in conjunction with the 

 Moon (Saturn 6° 12' S.). 

 ,, i6h. 45m. Sun enters Sign of Capricornus. 

 Winter commences. 

 25. 4h. 24m. Neptune in conjunction with the 



Moon (Neptune 5° 25' S.). 

 27. 2ih. om. Mercurv at greatest elongation 



W. of the Sun.' 

 31. i4h. om. Earth nearest the Sun. 



The Solar Motion Rel.xtively to the Inter- 

 stellar Absorbing Medium. — In Monthly Notices, 

 No. 9, vol. Ixxii., Prof. W. H. Pickering has a note 

 suggesting that the interstellar light-absorbing medium 

 may consist of material, gaseous molecules, rather 

 than being simply the sther, and should demonstrate 



