290 
ME. W. CROOKES ON THE ATOMIC WEIGHT OE THALLIUM. 
We have now the data for ascertaining the absolute values of the weights in terms of 
the (1000) weight taken as standard. Adding the equations a and b gives 
(1000) = 2(300) +(200)-)- 2(100) -j- 0-01777. 
Multiplying equation c by 2 gives 
2(300) = 2(200) +2(100)+ 0-01982. 
Subtracting e from d gives 
(200) =2(100) +0-01607. 
Now by («+&) + 2c + 3(d— e) we get 
(1000)=10(100) + 0-01777 + 0-01982 + 0-04827 ; 
(1000)=10(100) + 0-08580; 
.-. Ho go) = (100) + 0-008580 ; 
(100)= 100 -0-008580; 
(100) = 99-991420 grains A.* 
Substituting this value for the (100) weight, we get from equation e, 
99-991420 = (60) + (30)+ (10) — 0-00030 ; 
(60) + (30) + (10) = 99-991 720 B. 
From equation d we therefore get 
(200) = 99-991420 + 99-991720 + 0-01577 ; 
.-. (200) = 199-998910. . C. 
From equation c we get 
(300)= 199-998910 + 99-991420 + 0-00991 ; 
(300) = 300-000240. . D. 
From equation b we get 
(600) = 300-000240 +199-998910 + 99-991420 + 0-00777 ; 
.-. (600)=599-998340 E. 
Again, adding e and f, 
(100) = 2(30)+ (20) +2(10) — 0-00552 ; 
.-. from A, 
99 -991420= 2(30)+ (20) +2(10)— 0*00552. 
Multiplying g by 2, 
2(30) =2(20)+ 2(10) + 0*00308. 
* Although, these decimals are carried to the sixth place, the balance would not indicate beyond the fourth 
place. By taking the mean of ten interchanged weighings, I could obtain a fifth place. The calculated values 
of the weights were carried to a sixth decimal, in order to avoid inaccuracy in the fourth and fifth places when 
several values were summed. 
