298 EIGHTH REPORT— 1838. 



^' 7th. Are cast and wrought iron equally well protected ? 

 " 8th. Has it been tried in fresh water ? 

 ** The favour of your replies as early as convenient to these 

 queries will be esteemed by us." 



To which we received the following reply :- — 



" Dock Yard, Liverpool, 27th April, 1838. 

 " Sir, — I am in receipt of yours of the 25th instant, the con- 

 tents of which I have communicated to Mr. Hartley, sen., who 

 has directed me to inform you, that he has only a small portion 

 of the brass left that was attached to the cylinder that first 

 caused his attention to the preservative properties of that metal ; 

 and with regard to the series of questions put by you, I am de- 

 sired to say, that daring his son's absence his other avocations 

 are such as not to afford time or opportunity of properly attend- 

 ing thereto. 



" I am. Sir, your obedient servant, 



" Gilbert Cummins. 

 "To Mr. Robert Mallet." 



We hence were precluded from any information or assistance 

 from Mr. Hartley, and were about giving up all hope of expe- 

 rimenting on the identical brass stated to have been used at 

 Liverpool for protection, when we were unexpectedly favoured 

 by Professor Kane with a piece of this brass weighing about 

 tvvo pounds, which he stated had been personally handed to him 

 by Mr. Jesse Hartley ; with these the following selection of 

 experiments made by the writer, from amongst many others 

 made by Professor Davy and himself, may be stated with their 

 results. 



103. When a piece of cast iron was placed in a glass vessel 

 of sea water with a piece of this brass laid in close contact with 

 its upper side, the iron was rapidly attacked, the brass remain- 

 ing bright, and rust soon deposited in large quantity. 



104. An equal sized piece broken from the same specimen of 

 cast iron, and exposed in similar circumstances to sea water 

 alone, was much less acted upon by it. 



105. Two pieces of wrought iron similarly treated produced 

 similar results. 



106. Specimens of cast iron and of wrought iron similarly 

 treated, with and without the presence of the brass, produced 

 similar results, as above, in fresh ivater, but more slowly. 



107. Where the surfaces of the brass and iron were in close 

 contact, the iron remained nearly bright ; but it did so likewise 

 when a piece of plate-glass was substituted for the brass, or 



