ON COLOURING MATTERS. 65 
IL. 0°4670 germ. obtained by means of nitric acid and burnt with chromate 
of lead, gave 0°9865 carbonic acid and 0°1685 water. 
__ IIL. 0°4475 grm. of the same preparation as the preceding gave 0°9360 
carbonic acid and 0°1625 water. 
__ IV. 04895 erm., purified by means of chlorine and burnt with chromate 
of lead, gave 0°9335 carbonic acid and 0°1510 water. 
_ These numbers give in 100 parts— 
ie 
I. II. III. IV. 
SEDER av. 5,06 57°20 57°61 57°10 57°92 
Hydrogen.... 3°83 4°00 4°03 3°81 
Oxygen .... 38°97 88°59 38°87 38°27 
100°00 100°00 100°U00 100°00 
Alizarate of lead was analysed with the following results :— 
I. 0°8110 grm. gave 0°2665 oxide of lead and 0°2160 metallic lead, equi- 
valent to 0°4991 oxide of lead. 
0°6660 erm. gave 0°5810 carbonic acid and 0°0915 water. 
II. 0°6230 grm. gave 0°2040 oxide of lead and 0°1655 metallic léad, equi- 
valent to 0'3822 oxide of lead. 
- 0°6515 grm. gave 0°5560 carbonic acid and 0°0860 water. Hence was 
deduced the following composition :— 
Calculated cee 
Numbers. te IL 
i 14 eqs. Carbon .... 84 23°37 23°79 ° 23°27 
me|)6| 4 4, Hydrogen... 4 Ms 1°52 1:46 
G6 ,, Oxygen.... 48 13°37 13°15 13°93 
2 ,, Oxideoflead 223°4 62°15 61°54 61°34 
359°4 100°00 100°00 100°00 
in a water-bath. 
__ I. 0°6725 grm. of baryta salt dried at 212° gave 0°5245 sulphate of baryta, 
equivalent to 0°3442 baryta. . 
II. 0°7330 grm. gave 0°5700 sulphate of baryta, equivalent to 0°3740 
“Tks composition is therefore probably as follows :— 
Found. 
{ A Calculated. fo stat Ope 
Il. 
1 eq. anhydrous Acid. 136 46°26 
eRe Witter’ .). cajers ee 9 2°36 
2 eqs. Baryta ...... 153°3 51°38 51°18 51°03 
wi 298°3  100°00 
It is probable that the silver salt also contains two equivalents of base to 
one of acid. 
Calculated. 
14 eqs. Carbon ...ceeeessceee 84 57°93 
5.4, EAYGPOMEN, seceacsecsss 9 3°44 
Ts gp, OSU ant anis + 4cceea's JC 38°63 
145 100-00 
By the action of nitric acid on alizarin the latter takes up three equivalents 
