70 Scientific Intelligence. 
of indigotin. The yield is small, however, owing to the forma- 
tion of secondary products. With orthonitrophenylpropiolie 
acid however, the united action of an alkali and of a deoxidizing 
body is required, the reaction proceeding regularly : 
H,.NO,+H,=C,H,.NO+CO,+H,0. 
Bayer recommends the use of a mixture of glucose and an 
alkali carbonate. The transformation takes place at 110° C. 
and the indigotin separates in the crystalline form. Hence 
Bayer prefers the second process, But it has a still greater 
advantage, since the above reaction may be effected directly upon 
the cloth. The fiber is printed with a mixture of the orthonitro- 
phenylpropiolic acid, glucose and the alkali carbonate and is then 
exposed to superhe eated steam. The in igo blue is developed 
directly upon the fiber Aigoennine. This fact will give a arti- 
ficial indigo a great advantage r the natural stabi The 
spake: of producing other inaigothie es by effecting sieaaives 
tions in the phenyl group which it contains, "absence ce 
rests —Ann. Chim. Phys., V, xxi, 286, Oct.; 
n Isopropylene- newrine.—MoRtEy has os repos in the 
tiovaioes of . urtz, a neurine containing oxyisopropyl 1n 
place of the oxethyl in normal neurine. B action op 20 
neutral liquid resulted which gave a platinum salt of the compo- 
sition ©,,H,,N,O,PtCl, The propylene-neurine chloride crystal- 
lizes in colorless transparent crystals, very deliquescent, an 
which turn brown in the air.— Ber. Berl. Chem. Ges., xiii toy, 
; G. 
7. Notice of the investigation of Dr. J. W. Bevin on the 
Relations between the Molecular Structure of Organic Compounds 
and their ne i ower, (Liebig’s Annalen, excix, 139 and 
ecili, 1.)—The study of the relations between the physical proper- 
ties of chemical compounds and their molecular “dase has 
opened a new field to the science = sooyonan istry. A remarkable 
the results of the two investigations ne ite wholly harmonize wit 
one another; yet in both ¢ the new method of investigation 
is the chief point of tuneaiaii orn eters every reason to 
that by carefully comparing ‘the different aeeicas of solving the 
same problem the truth may ultimately be reac 
If we denote by the index of refraction of a body the excess of 
this index over unity or (“—1) represents what has been called the 
refracting power of a body, and since the refracting power increases 
in general with the density (6) we obtain by dividing the refracting 
power by the density a quantity i which is, essentially, 
independent of mere changes of physical condition, and depends on 
