388 Dr. Ure on Pharmaceutical Preparations of Iron, 



another material to be provided, prepared, and carted also ; 

 such expense, which I maintain is all unnecessary, and which 

 must make the principal item in the cost of payments I have 

 lately seen, may all be saved by this plan. 



A grand objection to a Macadamized pavement, in this and 

 every cold climate, is, that a severe frost setting in after wet, 

 does incalculable injury, owing to its porous state ; now, as no 

 water can penetrate beneath the surface of this pavement, if 

 properly made, this serious fault is obviated. 



I trust the strength and cheapness of this plan, as compared 

 with all others I have seen, will induce some one, having the 

 power, to grant it a trial, and I have no fear for the result. I 

 have observed that the most useful inventions are the most 

 simple and obvious when once made known ; and often, from 

 their very simplicity, take away from the merit of the inventor ; 

 we may instance steam, gas, &c. &c. As I publish my senti- 

 ments and observations, and the result I have come to, after 

 much trouble and attention, without any sinister motive, I 

 trust I may escape the imputation of having promulgated a 

 plan which any one could suggest ; should such casuists be 

 found, I refer them to the story of Columbus breaking the egg. 



September, 1829. 



On some Pharmaceutical Preparations of Iron, and particu- 

 larly the Tartrates. By Andrew Ure, M.D., F.R.S., 

 &c. &c. 



1. Tartaric acid has hardly any action on the red oxide 

 of iron, for though 200 grains of the former dissolved in water, 

 were digested on a sand bath on 50 grains of the latter, in the 

 form of the rubigo ferri of the shops, it became but faintly 

 coloured in the course of three days, and a very few grains 

 only of the oxide were taken up. The same rust of iron was 

 quite soluble in dilute muriatic acid. 



When tartaric acid, in solution, is digested on red oxide of 

 iron, prepared by nitric acid, no apparent combination ensues 



