86 



Blue Limestone, Hacheistown Valley, Warren county. 

 Description. — Colour, dull bluish gray ; texture, moderately 

 close grained, and slightly subcrystalline ; has interspersed veins 

 of calcareous spar. 

 Specific gravity. — 2-831 at a temperature of 69° Fahr. 

 Composition. — In 100 parts: 



Carbonate of lime, - 50-23 



Carbonate of magnesia, - 37-13 

 Alumina and peroxide of iron, 0-63 

 Insoluble matter, - 9-93 



Moisture and loss,^ - 2-08 



100-00 



The above five analyses refer, it need hardly be said, to Forma- 

 tion II., which will be found, I doubt not, upon an extensive 

 examination, to be more often magnesian than purely calcareous. 



Having shown the carbonate of magnesia to be an abundant 

 ingredient in many of the limestones, the lime of which is used 

 among the farmers of those districts for assisting the fertility of 

 the soil, it may be of some service to the agricultural interests 

 of the State, to endeavour in this place to correct the generally 

 prevailing impression, to this day widely propagated by writers, 

 of the injurious action of magnesian lime upon the land. It is 

 now clearly established, that a large propoi'tion of the lime 

 employed by the farmers of the southeastern counties of Penn- 

 sylvania, for a long series of years past, with such eminent 

 benefit to the permanent fertility of their soils, is, without their 

 being aware of it, highly magnesian. This is of itself enough to 

 refute the popular prejudice upon this subject. But the analyses 

 above given, of a number of those of New Jersey, of well known 

 repute as to their agricultural fitness, will enable the farmers of 

 Warren and Sussex counties in particular, to judge of the merits 

 of this question for themselves, by uniting with the chemical 

 results here presented, their own agricultural experience. While 

 the evidence from experiment and trial now brought forward, 

 goes conclusively to show, that the magnesia cannot be poison- 

 ous to the crops, agreeably to common belief, it still leaves an 

 interesting and useful question undetermined, whether the mag- 



