54 
DE. STENHOUSE ON LAEIXINIC ACID. 
Fig. 1. 
iron, which is very persistent. The hark of old larch trees contains very little larixinic 
acid ; hut the bark of the small branches, and that of the stems of the larch when not 
more than from twenty to thirty years of age, contains very considerable quantities of this 
substance, the concentrated syrup from the portions of bark yielding more larixinic acid 
than an equal weight of catechu does of oxyphenic acid. Larixinic acid, after it has 
been purified by sublimation, forms beautifully white crystals, often more than an inch 
in length, of a brilliant silvery lustre, very much resembling benzoic acid in appearance. 
They sublime at 93° Cent., and melt at 153° Cent. ; but its aqueous solutions volatilize 
at ordinary temperatm-es. I am indebted to the kindness of Professor W. H. Millee, 
of Cambridge, for the subjoined measurements of the crystals of larixinic acid. 
“ The crystals obtained by sublimation become rough so rapidly when 
exposed to the am, that very little confidence can be placed in the fol- 
lowing results : — 
“ The crystals belong to the oblique system ; they usually occur in 
twins, like the annexed figure. They are extremely thin in a direction 
perpendicular to h. Denoting by Z, m, n faces in the zone a Z>, and by r 
a face in the zone h c, it appears that tan b I, tan b m, tan b n are nearly 
as the numbers 2, 3, 6, and that «5=90° O', 5(7=90° O', «(7=76° O', 
5Z=49°29', 5m=60°20', 5 m= 74°6', 5r=75°30'. Cleavage a distinct, 
c imperfect. 
“ The crystals of larixinic acid crystallized out of water are very imperfect ; the angles 
must be regarded as very rough approximations. They are deduced, as w^ell as I could 
deduce them, from a mean of a considerable number of observations by no means agree- 
ing well with each other. The angle between the normals to two faces is taken as the 
measure of the angle between the faces. 
“ Oblique : — 
1 0 0, 1 0 1 = 26° 22' 
010, 
111 = 74° 36'; 
0 01,1 01 = 44° 20'. 
Fig. 2. 
“Forms observed: — 
010, 001, 110, 
oil, 02 3 
Oil 
Angles. 
110, 0 01 
o / 
= 71 58 
Uo 
Olo 
Uo 
010, 110 
= 69 35 
010 , oil 
= 59 37 
010, 02 3 
= 68 39 
010, 0 01 
= 90 0 
OoJ' 
“ Cleavage 0 01 distinct, and very easily obtained.” 
The smell of the aqueous solution of larixinic acid is sweetish, like that of a syrup, 
but the smell of the sublimed acid is veiy peculiar and slightly empyreumatic. As 
larixinic acid emits a sensible odour at ordinary temperatures, in this respect it con- 
