AMERICAN INSTITUTE. 489 



Prof. Hedrlck said, perhaps clilorine may be generated, or liydrocliloric 

 acid ; yet he did not think so ; some higher acid may do this -work. 



Mr. Tillman suggested that thermo-electric action may haA^e something 

 to do with it. 



Mr. Garvey submitted that it was useless to speculate or form theories 

 about this action upon marine boilers until the facts were ascertained, by 

 actual examination of a number of boilers, and- the collection' of well- 

 authenticated facts connected with boilers, their use, economy, &c. 



In view of the importance of the subject, a committee was appointed to 

 obtain information upon it, and report at some future time. Prof. Garvey, 

 Mr. Dibbln, Mr. Fisher, Prof. He^rick, and Mr. Seeley, were so appointed. 



Mr. Fisher asked if the phenomenon was of frequent occurrence, and 

 what was the peculiar nature of the iron in which it was observed — did it 

 contain sulphur, and was the action due to galvanic action ? 



Mr. Dibbin explained that, though boiler iron has failed in many instances, 

 interested parties avoided having their boilers examined, and consequently 

 the amount of information on the subject was very limited. He considered 

 the generation of a large quantity of steam, some of which became decom- 

 posed during its production, was a probable cause of the chemical action 

 upon the iron, some active element being liberated from the water. 



Mr. Seeley said that Dr. Deck, in examining air from Rj'erson's diving- 

 bell, Tiad found chlorine, though he could not see where it came from. 

 Pure iron in pure water will not rust ; it is the portion above the water 

 that oxydizcs, through the galvanic action of the circuit made up of the air, 

 metal, and water. In like manner, if iron be impure— contain some other 

 substance beside, iron in combination with it — the oxydation is more rapid. 

 Electricity has nothing to do with the mechanical efi'eets of steam ; and it 

 is absurd to talk of water being decomposed into a mechanical mixture 

 of oxygen and hydrogen, for they would unite and form water at the same 

 temperature that water could be decomposed at. 



Mr. Haskell. — There is a great difference between the salt in tliis coun- 

 try and in England ; iron is used there for salt-evaporating pans, it cannot 

 be so used here ; both sides of the ocean do not seem to be well mixed up. 



Mr. Seeley. — There is no doubt that water is decomposed when in contact 

 with red hot iron — the oxygen combining with the iron, and the hydrogen 

 being liberated; but hydrogen of itself can no more explode than carbonic acid. 



1 resident Rcnwick was glad that the vulgar errors which had been men- 

 tioned were confuted ; for it was unscientific and absurd to talk of water 

 being converted into explosive gases in a steam-boiler. It is well known 

 to i,nspectors of steam boats, that steam chimnies are very perishable. . 

 This arises from the action of the heated iron on the steam, »y which the 

 former is rapidly oxydated. But the hydrogen, which is thus liberated, is 

 no longer mixed with oxygen, and therefore cannot explode. 



Mr. Dibbln. — In the case I mentioned, the resultant gases are intimately 

 mixed, and they have strong affinity for each other, M'hich causes them, as 

 soon as the heat is lowered, to unite again into water or steam. 



