THE ALUMNI JOURNAL. 



37 



action. Attention has often been called 

 to the similarity of action of the inorganic 

 compounds of K.-Hg.-Fe.-Zn., also those 

 ot phosphorus, arsenic and antimony, 

 iron and manganese, zinc and cadmium. 

 Again comparing the alkali metals* 

 it has been shown, that the potassium 

 salts owe their more prompt action as com- 

 pared to those of soda, to their higher 

 molecular weight and greater electrolytic 

 conductivity ; from this the rubidium 

 salts may naturally be expected to take 

 a higher position for similar reasons. 

 The electrolytic conductivity of the 

 iodides of these metals show a similar 

 ascending progression like unto that of 

 the molecular weights thus : 



Element Na K Rb. 



Molecular Wt. 23 39 85.4 



Elect.cond. of iodides 105.7 128.5 130-6 

 Dilution 32. 



These data are said by Erdmann not 

 only to represent the actual and relative 

 rapidity with which the different iodides 

 are distributed throughout the organism, 

 under the influence of osmotic pressure 

 and electrical currents, but their data 

 also afford a direct measure of their 

 degree of medicinal activity, for physi- 

 logical activity is conditioned b}' the 

 ability to enter into chemical re-actions, 

 and according toOstwald'slaw, chemical 

 activity is proportional to the electrolytic 

 conductivity." This explains why the 

 practitioner prefers the potassium iodide 

 to the soda salt, although the latter con- 

 tains 85% iodine, compared to ']6% of 

 the former. Also upon these grounds 

 rubidium iodide, containing about 60% 

 iodine is receiving attention, it being 

 claimed to be far more active than either 

 of the other iodides. 



The apothecary classifies the organic 

 remedies according to their chemical 



*Erdmann Phar. Ceiith. '93-598. 



constitution as derivatives of methane, 

 benzene, etc., while the physician classi- 

 fies them according to their therapeutic 

 action on the organism as hypnotics, 

 antipyretics, etc. The chemist is en- 

 deavoring to find, if possible, a middle 

 way by studying the relationship between 

 chemical constitution and medicinal 

 action, which will enable him to build 

 up and construct bodies of known definite 

 physiological action. Anything in the 

 way of a general chemical classification, 

 leads to diflSculties, as will be seen in 

 that of Dujardin-Beaumetz ; he classed 

 the aromatic hydroxyl derivatives as 

 (phenol, napthol, etc.), as having anti- 

 septic properties. Amido derivatives as 

 (acetanilid, kairin, thallin, etc.), anti- 

 pyretics, and such compounds in which a 

 hydrogen in the amido group is replaced 

 by a fatty radical, (particularly methyl), 

 as hypnotics, as antipyrin, exalgin 

 (methyl-acetaiiilid), phenacetin, (acet- 

 phenetidin), etc. As was pointed out by 

 Ville, such a classification is incorrect 

 from a chemical standpoint, for the 

 bodies classed under the amido group do 

 not belong together, for acetanilid con- 

 tains nitrogen in the side chain, while in 

 thallin and kairin it is in the nucleus, as 

 a chinoline derivative. Likewise exalgin 

 and phenacetin are derivatives of anilin 

 while antipyrin is a derivative of pyrazol. 

 Again Hodgkin classified the methane 

 derivatives and aldehydes as hypnotics 

 and anaesthetics while tliose of the ben- 

 zene series were classed as antipyretics 

 and antiseptics ; such a classification of 

 chemical constitution and physiological 

 action is too general and very misleading, 

 for as we have already said, the physio- 

 logical action of such bodies depend on 

 the construction of their molecules and 

 not great groups. I will now endeavor 

 to present a general outline of what has 

 been done in this direction. In order to 

 render the subject as lucid and concise 



