380 Scientific Intelligence. 



determined by interposing an apparatus giving colored rings by- 

 means of thin layers of air. Attempts have been made, as yet 

 without success, to form a phosphorescent eye-piece like the fluo- 

 rescent eye-piece of Mr. Soret. — -Bib. Univ., ccxxviii, 306. 



11. Fluorescence.— M. Lommei., continuing his researches on 

 fluorescence, arrives at the following conclusions: — 1. There are 

 two kinds of fluorescence. In one, each homogeneous ray falling 

 within the limits of the fluorescence -pi-.-tnim excites not only 

 rays of greater and equal. !>ut also waves of shorter wave-length; 

 the latter, so far as they belong to the region in question. In the 

 second kind each homogeneous ray excites oiilv r:iv< .if greater or 

 eqi I wave-length. 2. There are substances which have only the 

 first kind of fluorescence; each c.veitant i;tv excites the whole fluo- 

 rescence spectrum. Hence they are not subject to Stokers law. 

 Such are napl ,vll and eosin. 3. There are sub- 

 stances which have only the second kind of flu 

 which therefore throughout their fluorescence 

 Stokers law. Such arc most of the fluorescent 

 erto examined. 4. There are substances which have both kinds 



ace, so that the first kind is proper to a certain por- 

 tion of their fluorescence spectrum, and the second kind proper to 

 their remaining parts. Hence these o'.ev Stokes's law only in 

 par?. Si, eh are chamdelin red, Mue and •••reen. — !'<»(</. . Inn., clix, 

 514; Xntn e, xv. 441. * " J B . c. P. 



12. On the fr f t<;i;hri>i!,i of het< ,■<>>/, „, ,na .^il^t.uo-es ; by J. 

 Wjllakd (iiBus, of Yale College. 141 pp. 8vo.— The paper on 

 this subject by Profess* t < i iU>-. nuhlished in volume iii. of the 

 Transactions of the Connecticut Academy of Sciences (1876), re- 

 ceived the following exposition bv Professor J. Cler 



of ( andu-idge. Knglaud, in his lecture on the occasion of the recent 

 hition : 





' The thermodynamic?*] problem of the equilibrium of heteroge- 

 3us substances was attacked hy KirehhoiF in 1855, when the 



followed by 



yet in its infancy, and his method 



ribbs, of Yale College, Connecticut, 



me to be more likely than any others to enable us, without any 



to comprehend the relations between the 



different physical and chemical states of bodies, and it is to these 



< In studying tl <• i,n,p.. r i j, s ..fa lc.mo._r, M ,.„us lines of fluid, con- 

 sisting of n „, I'rofcsv,,r <Tihl.s takes a- ids 

 ■*' b r „ energj ofth il i !. b depeo i on tta vol- 

 unie and entropy tog- th-r with the masses, m , m 2 .' . . . "'„, of 

 its n compon. i K these „ + i <, .,ii .'■> . ., ,, , _ ,, ;, | :is ,„.h r n- 



