Dr. A. W. Hofman on Bases in Coal-gas Naphtha. 193 



lumn4, 173 — 80 = 93; thus my supposition confines the errors 

 on the greater or positive side within narrower limits. 



The constant deduced from each limit separately varies be- 

 tween 1 '063983 and 1 '129124 after no apparent law; the 

 arithmetical means are 1*0875431050,000, 1*085334 to 100,000, 

 1-082687 to 500,000, and 1*081956 to 1,000,000, indicating 

 an average decrease. 



It is likewise known that — V% = / e~ dt, t being any 



number; .*. we obtain this form: 



xe 



' 2 /, 10 



dt = — < 



London, January 29, 1844. 



8. M. D. 



XXXIV. A Chemical Investigation of the Organic Bases con- 

 tained in Coal-Gas Naphtha. By Dr. Augustus William 

 Hofman, Assistant in the Giessen Laboratory. 

 [Continued from p. 128.] 

 Combinations of Cyanol. 

 7V[ ONE of the other organic bases afford crystallizable com- 

 ■^ pounds with such facility as cyanol. In this respect the 

 perfectly pure base differs from that mixed with the smelling 

 Phil. Mag. S. 3. Vol. 24. No. 1 58 . March 1 844. O 



