456 TRANSACTIONS OF THE AMERICAN INSTITUTE, 



earth's centre, leaving the surface barren. Were it not for car- 

 bon and alumina, our wells would all become cesspools. Through 

 sea sand, with one per cent of finely divided charcoal, the brown 

 liquor of the barnyard may be so filtered as |to become colorless 

 and inodorous. Damp charcoal will take up from forty to sixty 

 times its volume of gases of various kinds. Place under a bell- 

 glass a saucer of charcoal and another of volatile carbonate of 

 ammonia, and when the saucer of ammonia becomes entirely 

 empty, the charcoal will be found to have taken it all up. You 

 cannot smell it, nor wash it out of the charcoal. But place the 

 root of a living plant in that charcoal and render it humid, and 

 then you will perceive that the plant has the power of taking it 

 out. 



Mr. Carpenter inquired whether bone-black, applied eight years 

 ago, could now begin to affect the soil. 



Prof. Mapes. — Yes ; but not the bone-black per se. Bone- 

 black has no earthly value in its natural state ; but if one atom 

 of lime be taken away, rendering it a super-phosphate, it will 

 then begin to act. Josiah Stickney, twenty years ago, applied 

 400 tons of bone black to his land, and after fifteen years he 

 began to see a little effect. Now, when he applies extremely 

 dilute sulphuric acid, it forms a phosphate, and he obtains large 

 results. Any manure applied to a piece of land containing bone- 

 black should be moistened with dilute sulphuric acid, which will 

 render the bone-black active. By dilute, I mean truly dilute ; 

 one part acid and a thousand parts water. 



On the mountains where they formerly made charcoal, all 

 around the old charcoal hearths will be found spots where the 

 cattle get the first bite of grass in the spring. I contracted with 

 the New Jersey railroad company for a number of years to give 

 me a couple of loads or more ot charcoal cinders per week. 

 When applying phosphates to the soil, I use them as a divider, 

 and then sow them in with the phosphates. Charcoal should be 

 kept in the manure shed all the time. It should underlie the 

 bedding of the horses, be thrown in the urine troughs, and thus 

 prevent wastage. 



Dr. Trimble. — If a farmer keeps stock enough to furnish all 

 the stable manure required by the land, does he require any 

 other manure ? 



Prof. Mapes. — No, sir ; but he would find it better to apply 

 something else, because in some particulars his soil would dete- 



