62 REPORT—1848. 
water of crystallization, crystallized alizarin was heated in a water-bath until 
it lost no more in weight. 
I. 0:4015 orm. treated in this way lost 0°0735 water. 
II. 0°3575 grm. lost 0°0655 water. 
Alizarin which had been deprived of its water of crystallization by heat, 
gave, on being burnt with chromate of lead, the following results :— 
I. 0°2990 grm. gave 0°7575 carbonic acid and 0°1045 water. 
II. 0°3005 grm. of a different preparation gave 0°7620 carbonic acid and 
0°1095 water. 
III. 0:2765 grm. of the same preparation as the preceding gave 0°7010 
carbonic acid and 0°1025 water. 
In 100 parts it contains therefore— 
I. Il. Il. 
Carbon ....eceeee- 69°09 69°15 69°14 
Hydrogen ....-.se8. 3°88 4°04 4°11 
Oxygen ...eeeeeeees 27°03 26°81 26°75 
100°00 100°00 100°00 
On analysing alizarin prepared by sublimation from pure crystals, I ob- 
tained the following numbers :— 
I. 0°3970 grm. gave 1:0115 carbonic acid and 0°1340 water. 
II. 0°4110 grm. gave 1°0510 carbonic acid and 0°1375 water. 
In 100 parts— 
IC II. 
7 Carbon .....ccccecess 69°48 69°73 
Hydrogen ........-- os = =8°75 3°71 
Oxygen .....ecceeesss 26°77 26°56 
100°00 100°00 
It will be seen from this that sublimed alizarin does not differ materially in 
composition from alizarin which has been freed from its water of crystalli- 
zation. 
Of the compounds of alizarin with bases I prepared the lime, baryta and 
lead compounds. The two former were prepared by dissolving alizarin in 
ammonia, and precipitating with chloride of calcium and chloride of barium, 
the latter by dissolving alizarin in alcohol and precipitating with an alcoholic 
solution of sugar of lead. The latter forms a purple precipitate, which, after 
standing for some hours, becomes of a dull red. 
The lead compound gave on analysis the following numbers :— 
I. 0°4800 grm. gave 0°2095 oxide of lead and 0°0245 metallic lead, equi- 
valent to 0°2359 oxide of lead. 
0°5125 grm. burnt with chromate of lead gave 0°7050 carbonic acid and 
0°0780 water. 
II. 0°5865 grm. of a different preparation gave 0°3970 sulphate of lead, 
equivalent to 0°2920 oxide of lead. 
0°6915 grm. gave 0°9370 carbonic acid and 0°1005 water. Hence was 
deduced the following composition :— 
Found. 
Calculated i 
Numbers. q Ir 
14 eqs. Carbon..... . 84 37°57 87°51 36°95 
4 , Hydrogen .. 4 1°78 1°67 1°61 
3 ,, Oxygen .... 24 10°75 11°70 11°65 
1 ,, Oxide of lead 111*7 49°90 49°12 49°79 
223°7 100°00 100°00 10000 
