30X Dr. Schunck on some Products 



0*5435 grm. gave 0*5175 grm. chloride of platinum and 

 ammonium. 



Hence it is to be inferred that the formula is C 28 H n N0 4 , 

 which requires 



Calculation. Experiment. 



C 28 168 74-66 74*16 



H u ii 488 4*95 



N 14 6-22 5-98 



4 32 14*24 H'9 1 



225 IOO'OO IOO'OO 



This formula leads to the conclusion that the formation 

 of the compound is due to the union of 1 at. of indigo-blue 

 with 1 at. of alcohol and 2 ats. of acetic acid, and the elimi- 

 nation of 8 ats. of water ; for 



Indigo-blue. Alcohol. ' Acetic acid. 



C 28 H u NO 4 +8HO=C 10 H 5 N0 3 +C, H c 2 4- *(C 4 H 4 4 ). 



D. 



This body is formed in abundance during this process ; and 

 I think it probable that its composition is always the same, 

 as the following analytical results will tend to show: — 



I. 0*3540 grm. of the substance, dried at 100° C, and 

 burnt as usual, gave 0*9360 grm. carbonic acid and 0*1635 

 grm. water. 



0*5630 grm. gave 0*5540 grm. chloride of platinum and 

 ammonium. 



II. 0*2325 grm., prepared on another occasion, gave 0*6030 

 grm. carbonic acid and 0*0985 grm. water. 



0*5700 grm. gave 0*5435 grm. chloride of platinum and 

 ammonium. 



The formula with which these numbers most closely cor- 

 respond is C 56 H 24 N 2 O 10 , which requires the following values — 



^ -, t ,. Experiment. 



Calculation. j t jj 



C.56 336 7179 72*11 7073 



H 24 24 5'i2 5i3 47o 



N 2 28 5-98 6-i8 5-98 



O 10 80 17-11 16-58 18-59 



468 IOO'OO IOO'OO ioo-oo 



The deficiency of carbon in the second analysis may be 

 partly due to the extreme difficulty with which the combus- 

 tion of the substance is effected — a difficulty which is always 

 experienced in the case of such bodies as become charred 

 when heated without previously melting. 



If the formula of C, C 28 H n N0 4 , be doubled, it will be 

 found to differ from that of D merely by 2 HO less. The for- 

 mation of both bodies is therefore to be explained in the same 



