derived from Indigo-blue. 305 



manner. The body C may, indeed, be regarded as the 

 anhydride of D, the resemblance between the two substances, 

 in their appearance and properties, being so great that it 

 is only by their behaviour to caustic alkalies that they can be 

 distinguished. 



E. 



Of this body I only obtained a quantity sufficient for two 

 analyses, and I must, therefore, leave it doubtful whether its 

 composition is uniform or not. 



I. 0*4355 grm. gave 1-1050 grm. carbonic acid and 0*1770 

 grm. water. 



0*5995 grm. gave 0*5740 grm. chloride of platinum and 

 ammonium. 



II. 0*4685 grm. gave 1*1890 grm. carbonic acid and 0*1930 

 grm. water. 



0*5615 grm. gave 0*5560 grm. chloride of platinum and 

 ammonium. 



These numbers lead to the formula C 28 H n N0 6 , which 

 requires 



Calculation. 



C 28 168 6970 



H n 11 4'56 



N 14 5-80 



6 48 i9"94 



Experiment. 

 I. II. 



69-20 



69*21 



4-5i 

 6*oi 



4'57 



6"2I 



20*28 



20'OI 



ioo*oo 



IOO'OO 



241 IOO'OO 



If this formula be correct, it follows that 2 ats. of indigo- 

 blue combine with 1 at. of alcohol and 5 ats. of acetic acid in 

 order to form, after elimination of 14 ats. of water, 2 ats. of the 

 body E, since 



Indigo-blue. Alcohol. Acetic acid. 



a(0 M H 11 N0 6 ) + i 4 HO=2(C ie H 5 NO a )+C 4 H fl O a +5(C 4 H 4 O 4 ). 



On comparing the formula of E with that of C, it will be 

 seen that the former merely differs from the latter by 2 ats. 

 oxygen, so that C + 20=E. 



Anthranilic Acid. 



Though there could be no doubt, after an examination of the 

 properties of the crystallized acid formed in this process, of its 

 identity with anthranilic acid, still I conceived that its analy- 

 sis, if not altogether indispensable, might prove of some in- 

 terest. The results obtained were as follows : — 



I. 0*3135 grm., dried at 100° C, gave 0*7035 grm. carbo- 

 nic acid and 0*1500 grm. water. 



0*4050 grm., burnt with soda-lime, gave 0*2890 grm. 

 metallic platinum. 



Phil. Mag. S. 4. Vol. 30. No. 203. Oct. 1865. X 



