CARBON. 79 



Filled with CO, it held the following weights, which give the accom- 

 panying densities : 



IVL CO. Density. 



2.8470 -96705 



2.8468 .96698 



2.8469 .96702 



Mean, .96702, zh .000015 



Combining this density with Leduc's determination of the density of 

 hydrogen, 0.6948, ± .00006745, it gives for the atomic weight of carbon : 



C ;= 11.957, ± .0270. 



Leduc himself combines the data with the density of oxygen, taken as 

 1.10503, and finds C = 11.913. In either case, however, the ])robable 

 error of the result is so high that it can carry little weight in the final 

 combmation. 



For carbon, including all the foregoing series, we now have the sub- 

 joined ratios : 



(i.) Per cent. Ag in silver acetate. .. . 64.636, ±.0007 

 (2.) " " tartrate.... 59.2806, =b .0014 



(3.) " " racemate.. 59.2769, nfc .0012 



(4.) " " malate .... 62.0016, zb .0096 



(5.) " " benzoate.. . 47.125, rt .0012 



(6.) Ag : CO.2 : : 1. 00 : 0.40723, zh .000071 

 (7.) C : O2 : : 1. 00 : 2.6659, i .0001 

 (8.) O : CO : : 1. 00 : 1. 75029, =fc .00005 

 (9.) Density of CO (air^ i), 0.96702, zh .000015 



Now, computing with = 15.879, ± .0003, and Ag = 107.108, ± .0031, 

 we get nine values for the atomic weight of carbon, as follows : 



From (1) C=ii.92i, zb .0012 



From (2) " = 11.967, zb .0019 



From (3) " = 11.973, ± .0017 



From (4) " = 11.972, zb .0098 



From (5) " ^ 11-917. ± .0008 



From (6) "=: 1 1.860, zb .0077 



From (7). . . " = 1 1. 913, ± .0006 



From (8) " = 11. 914, zb .0010 



From (9) " ^ 1 1 .957, zb .0270 



General mean C ^= 11.920, zb .0004 



If = 16, this becomes C = 12.011. 



