232 SCIENCE PROGRESS 



substances, which all occur naturally, a large number of allied 

 bases have been prepared by Stolz (Ber. 1904, 37, 4149), Dakin 

 (Proc. Roy. Soc. B, 1905, 76, 491), Barger and Jowett (Journ. 

 Chem. Soc. 1905, 87, 970), Pauly and Neukam {Ber. 1908, 41, 4151), 

 Bottcher (Ber. 1909, 42, 253), Tutin, Caton and Hann (Journ. 

 Chem. Soc. 1909, 95, 21 13), Johnson and Guest (Amer. Chem. 

 Journ. 1909, 42, 340), Rosenmund (Ber. 1909, 42, 253), Pyman 

 (Journ. Chern. Soc. 1910, 97, 268), Mannich and Jacobsohn (Ber. 

 1910, 43, 189), Mannich (Arch. Pharm. 1910, 248, 127), Walpole 

 (Journ. Chem. Soc. 1910, 97, 941), Barger and Ewins (ibid. 1910, 

 97, 2253), Rosenmund (Ber. 1910, 43, 3412) and Moore (Journ. 

 Chem. Soc. 191 1, 99, 416). 



Of the various synthetic bases only three have found a 

 limited application as substitutes for adrenaline, namely ethyl- 

 aminoacetocatechol (OH) 2 . C 6 H 3 . CO . CH 2 . NH . C 2 H 5 , amino- 

 ethanolcatechol (OH) 2 . C 6 H 3 . CH(OH) . CH 2 . NH 2 and 

 methylaminoethylcatechol (OH) 2 . C 6 H 3 . CH 2 . CH 2 . NH . CH 3 ; the 

 first two were prepared by Stolz, the latter by Pyman. 



This extensive series of more or less closely related com- 

 pounds, however, is chiefly of interest on account of the informa- 

 tion it has given with regard to the question of the relationship 

 of chemical constitution to physiological action. This problem 

 is of great theoretical as well as of practical interest and has led 

 to numerous investigations. Unfortunately, very few generali- 

 sations of any value can be deduced from the large number of 

 isolated facts which have been brought to light. Even if we 

 limit ourselves to a single well-defined type of activity, it is 

 almost impossible to predict the physiological effect of any 

 newly synthesised substance. The difficulty is particularly 

 well illustrated by the series of adrenaline-like bases now 

 under discussion. Their physiological action is in all cases 

 of the same type and we might expect that, as by successive 

 steps we approach nearer and nearer to the molecular structure 

 of adrenaline, each step would bring about an increase in 

 physiological activity. This is not so ; there is indeed a great 

 augmentation of activity in passing through the series but it 

 is not regular. One and the same modification of structure 

 enhances the activity of some compounds, while it leaves that 

 of others unaffected. Almost any departure from the structure 

 characteristic of adrenaline lowers the activity and we get 

 the impression that natural adrenaline is necessarily also 



