AMERICAN INSTITUTE. 349 



Part of this table may require explanation. 1st. ("Silex, clay, 

 iron, manganese, are excluded in all the following.") There being heavy 

 beds of sand and clay, mixed with much iron, associated with these marl 

 beds, we have no means of judging how much of each of these ingredients 

 is adventitious. The quantity of manganese is not given in the analysis, 

 the object being to compare this marl with the inorganic constituents of 

 vegetables. Those substances, together with the water, were excluded from 

 the analysis, and the remaining constituents, (viz : lime, magnesia, potash, 

 soda, phosphoric acid, and sulphuric acid,) were reduced to percentages, 

 as if these constituted the whole mass. 



2d. These six ingredients are separately given for the nine specimens, of 

 which the analysis are reported in. the geological survey of the State of 

 New Jersey, 1856, pp. 85 to 89. 



3d. The tenth column gives the mean of the nine specimens. 



4th. The eleventh column gives the mean results of the analysis of eleven 

 kinds of seaweed, from Johnson's Agricultural Chemistry, 2d edition, 

 Edinburgh, 1847, page 403. These are reported in a different form from 

 the analysis of marl ; they were, therefore, first reduced by chemical 

 equivalents to the same terms ; then the same materials excluded as in the 

 case of the marls, and the remainder divided into percentages, as if they 

 constituted the entire mass. 



5th. The line marked " percentage of the mass," 14.75 for the Squan- 

 kum marl, and 14.11 for the mean, and 97.7 for the ash of seaweed, shows 

 the percentage of the whole specimen produced by the six specified ingre- 

 dients. 



6th. The line marked " gross weight of equal worth," 6.62 for the first, 

 7.05 for the mean, and 1.00 for the seaweed, shows how many pounds of 

 the first, or of the mean, are equal in worth to one of the ashes of seaweed 

 (barilla ;) or how many tons of the particular marl we must transport, or 

 apply to the land, to equal one ton of barilla. 



7th. The line " cost of barilla, per 2,000 lbs., when marl costs ten cents 

 per bushel," ^16.95 for the first, $18.04 for the mean, shows the price we 

 pay for 2,000 lbs. of kelp, or barilla, contained in the marl, when marl 

 costs ten cents per bushel. The present cost of barilla itself is $45 per 

 ton. The price, ten cents per bushel, was adopted as the cost to myself at 

 the dock, (seven cents for the marl, and three cents freight ;) but it will 

 answer for any other rate per bushel by a very short calculation. Thus 

 Dowing, 1848, p. 404, says that " marl is sold at the pits near Burlington 

 at twenty-five cents per load, and delivered from sloops at seventy-five 

 cents per ton." (Ton is twenty-five bushels of eighty lbs.) The first rate 

 being one cent, they can afford to pay but one-tenth of the price stated for 

 a ton of barilla, or $1.77, as compared with the mean of the marls at the 

 pits ; or at the dock, three cents, they can pay $17.73x3-10 — $5.3-19 per 

 ton for barilla, to have the same value of useful ingredients, as for the 

 same money expended in marl. 



8th. In addition to the columns in the table, I made part of a calcula- 



