434 TRANSACTIONS OF THE 



The finishing coat is the same as is used on other -walls. One-fourth of 

 hydraulic cement to three-fourths of lime was used in the mortar for the 

 base of the walls for about two feet in height, to prevent the action of eap- 

 ilary attraction, and so allow the upper parts of the walls to dry. I have 

 called the attention of farmers to the value of hydraulic cements in forming 

 concrete fences, the sand to be used, being purely siliclous and free from 

 loam. The mortar must be kept before use for some time, for, if we use 

 dry lime and dry sand, there can be no chemical union between them. Wet 

 them and a silicate of lime is formed. Several gentlemen expressed the 

 opinion that the public should be more fully informed as to the objects of 

 this Association, and the mode in which these objects are sought by open 

 discussions free to the public. Accordingly, on motion of Mr. Garbanati, 

 it was resolved "That the chair be requested to appoint a committee of 

 three to consider and devise the best means of bringing the proceedings of 

 this Association, more directly before the public." 



The committee appointed by the chair, were, Mr. Stetson, Dr. Reuben, 

 and Prof. Hedrick. 



The regular subject of the evening being now in order was called up. 



IRON, STEEL AND MALLEABLE IRON. 



Dr. Yanderweyde introduced the subject by saying "Mr. President, 

 since our last meeting I have spent all the time I could spare in seeking to 

 satisfy my own mind as to the real nature and differences of iron, steel and 

 malleable iron, I find more books treating on these metals, than I could 

 read in six years. Several of these are of no value, as their information is 

 not up to the practical standard of the present day. 



Steel is a very difficult material to analyze, to determine whether it con- 

 tains carbon, aluminum, or silex, &c. It is also extremely hard to de- 

 termine whether there is nitrogen in steel or not. My impression is, that 

 there is. Professor Dumas has conclusively proved that nitrogen combines 

 with iron. I find that iron combines with almost all the metals. Gold 

 combined with copper, makes an alloy harder than either ingredient. Cop- 

 per alloyed with zinc forms brass, a harder substance. Copper with tin, 

 becomes harder in the form of composition, as also in that of bell metal. 

 From one to three parts in a hundred of chromium combined with iron 

 converts it into a kind of steel resembling meteoric iron. We know the 

 value of a small percentage of aluminum in forming "Wootz Steel," 

 Also cast iron with ten per cent, of platinum will make a good steel. 



Mr. Stetson supposed that the steel may, in the process of reduction, 

 obtain a small amount of aluminum from the clay of the crucibles. 



Dr. Vanderweyde stated that Professor Dumas took some fine iron wire, 

 and sealed it hermetically. He then heated the wire and poured upon it 

 a stream of ammoniacal gas, which was decomposed, and the nitrogen was 

 found to combine with the iron in the proportion of one atom of nitrogen to 

 two of iron, the resulting compound being a brittle and hard steel possess- 

 ing magnetic properties, but being deficient in some of the usual proper^ 

 ties of steel. 



