No. 7. DEPARTMENT OF AGRICULTURE. 439 



of Allegheny, Columbia, Lehigh and Northampton, with one large 

 plant in Lawrence count3\ The latter secure their natural product 

 from two or three different sources, and by judicious, skillful mixing 

 obtain the desired result. This could well be done in other parts 

 of Pennsylvania. 



The constituents for a commercial Portland cement are: Lime, from 

 60 to 64 per cent., silica, 20 to 24 per cent., alumina, 6 to 10 per cent., 

 iron oxide, 3 to 5 per cent., the oxide of magnesia from one-half of 

 one per cent, to not exceeding 3^ per cent., and sulphuric oxide to 

 not exceeding 2^ per cent. 



There are many limestone deposits in the State containing more 

 tlian 60 per cent, lime, whereby the skillful mixing of pure silica 

 gand or sand rock, and the addition of one or two other constituents, 

 a perfectly desirable Portland compound could be had. This is 

 notably so in Blair, Bucks, Carbon, Centre, Clinton, Columbia, 

 Cumberland, Dauphin, Franklin, Fulton, Huntingdon, Lancaster, 

 Monroe, Montgomery, Northumberland, Schuylkill, Union and York 

 counties. If a bulletin were published of the localities of the lime- 

 stones in those counties, together with analyses, and full descrip- 

 tions of what are essential to make complete the component parts 

 of the best cements, numerous mammoth plants would spring up as 

 by magic to add much to our already great industrial wealth. 



SALT AND BROMINE. 



One year ago attention was called to the annually decreasing salt 

 production of Pennsylvania, and to the possibility of extracting 

 it at a profit from brine in 38 of our counties. Also to the high order 

 of bromine found in Pennsylvania salt, particularly from the salt 

 water of the deeper wells west and northwest of the Allegheny 

 Mountains. The publishing of the report has not, thus far, led 

 to increased production of Pennsylvania prepared salt or bromine. 

 Once our State sent out superior salt to as distant places as New 

 Orleans; now very little goes beyond our borders. Indeed there is 

 so little manufactured that very few of our citizens know there is 

 Pennsylvania refined salt, and fewer still have ever seen any. Last 

 year, in January, bromine, extracted from Pennsylvania salt, sold 

 at 28 cents a pound; this year it brings 48 cents per pound. The 

 production is far behind the demand, owing to the increased con- 

 sumption for medicinal uses, for treatment of gold ores in the form 

 of bromo-cyanide, and the enlarged field for potassium bromide. It 

 seems somewhat odd to one who has studied the subject carefully 

 that the old, deep-drilled wells are not utilized for the manufacture 

 of salt and bromine in such counties as Cambria, Clarion, Crawford, 

 Elk, Erie, Fayette, Forest, Somerset and Westmoreland. The in- 

 creased market for bromine alone should spur to action; and we 

 ought not to allow our sister states Michigan, Ohio and West Vir- 

 ginia to completely monopolize so important an industry. 



RADIUM. 



Partly due to the wide-spread interest in the discovery of the 

 element, radium, some search has been made in our State for radium- 

 bearing minerals. Tyro counties produce them, Adams and Sohuyl- 



