490 TRANSACTIONS OF THE 



Mr. Garvey said, tliat the air in water contains more osygen than ordinary 

 air, and there is no proof that that oxygen is taken up by the red hot iron 

 in addition to oxygen from water. May not the oxygen mix with the hydro- 

 gen from the decomposed water, and so give an explosive mixture ? 



. Prof. Renwick.— The fact is well known that red-hot iron will decompose 

 water. The experiment illustrating this, is performed every season in all 

 courses of chemistry. And, if a proof be required to show that water can 

 be decomposed by heat into a mechanical mixture of oxygen and hydrogen, 

 it must be given by the advocates of that theory. We can give a strong 

 fact to show that such a change is highly improbable, or, in fact, impossible. 

 Perkins heated a vessel of water until it was incandescent, and would not 

 escape through an opening made in the side of the vessel, and yet it re- 

 mained water ; the vessel was full, and when cold, the water was still un- 

 decomposed. 



On a former occasion, I heard a full and satisfactory account of the 

 causes of boiler explosions, I think, from Prof. Garvey. 



Mr. Dibbin, in illustration of his remark, that the lower stratum of water 

 is colder than the upper, mentioned the fact, that a tea-kettle, when boiling, 

 may be removed from the fire, and the hand placed upon the bottom without 

 fear of burning. After several remarks upon this phenomenon, it was pro- 

 posed to try the experiment next night. 



Mr. Hedrick then introduced a point with reference to the use of super 

 heated steam, which gave rise to several suggestions. 



The subject for the next meeting was then agreed upon, viz : Paints 

 used to preserve Roofing ; Mr. Seeley to read a paper. 



Polytechnic Association of the American Institute, ) 



November 17, 1859. ( 



S. D. Tillman, Esq., In the chair. John Johnson, Esq., Secretary, pro 

 tem. 



After the reading of the minutes of last meeting, Mr. Johnson exhibited 

 some water in the spheroidal state. The experiment was as follows : Hav- 

 ing heated a copper dish to a high temperature, he introduced a large 

 globule of water, which, instead of flowing over the bottom of the dish and 

 wetting it, remained suspended in its own vapor at a short distance above 

 the dish, and jumped about, assuming different forms and evaporating 

 comparatively slowly. Mr. Johnson Stated that water exhibits an attrac- 

 tion for almost all substances, at low temperatures, and consequently wets 

 them; but that, at high temperatures, it will not wet them, but assumes 

 what has been called the spheroidal state, from the resemblance of the water 

 globule to a sphere. The phenomenon is familiar to all persons who have 

 noticed water falling upon a hot stove, or saliva thrown upon a flat iron to 

 test its temperature. Leidenfurt, in 1756, investigated the phenomena 

 presented by water in the spheroidal state ; and more recently M. Bou- 



