214 Dr. Schunck on Colouring Matters. 



to that of benzine, and give, as a product of the decomposition, a 

 thick brown oil, to which without doubt the smell is owing ; while 

 the carbonates of the bases, or the bases themselves, remain behind 

 mixed with much charcoal. 



The elementary analysis of alizaric acid gave the following re- 

 sults : — 



I. 0*5250 grm. obtained by means of perchloride of iron and 

 burnt with oxide of copper, gave 1"1015 carbonic acid and 0-1810 

 water. 



II. 0-4670 grm. obtained by means of nitric acid and burnt with 

 chromate of lead, gave 0-9865 carbonic acid and 0-1685 water. 



III. 0-4475 grm. of the same preparation as the preceding gave 

 0*9360 carbonic acid and 0-1625 water. 



IV. 0*4395 grm., 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 — 



I. II. III. IV. 



Carbon 57*20 57-61 57*10 57*92 



Hydrogen 3*83 4*00 4*03 3*81 



Oxygen .... 38*97 38*39 38*87 38*27 



100-00 100-00 100-00 100*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, equivalent to 0*4991 oxide of lead. 



0*6660 grm. gave 0*5810 carbonic acid and 0*0915 water. 



II. 0*6230 grm. gave 0*2040 oxide of lead and 0*1655 metallic 

 lead, equivalent 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 ^T*^* 



359-4 100-00 100*00 100*00 



The baryta salt lost nothing in weight on being heated for several 

 hours 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 baryta. 



Its composition is therefore probably as follows : — 



Found. 



Calculated . 



II. 



1 eq. anhydrous Acid . 136 46-26 



1 „ Water 9 2-36 



2 eqs. Baryta 153*3 51*38 51*18 51-08 



298*3 100*00 



