428 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



and the particular constituents that crossed it in the opposite 

 one, I could get at the precise mixture that that twenty feet 

 square represented. Then I began with that mixture, instead of 

 guano, on a new plot 200 feet square, and crossed it again with 

 the constituents, as before, and again found that I had one, two, 

 or three squares better than all the others ; and, again calcula- 

 ting the mixture producing the best square, I tried again. I con- 

 tinued thus four 3^ears most faithfully, until, at last, I arrived at 

 a mixture that produced results alike all over the squares. With 

 that mixture I manured a piece of ground, which several mem- 

 bers of this Institute examined, and which, though the mixture 

 was put on thirteen years ago, retained its fertility for many 

 years. The mixture was composed of 100 pounds of calcined 

 bones, treated with 56 pounds of sulphuric acid, to which were 

 added 36 pounds of Peruvian guano, and 20 pounds of the sul- 

 phate of ammonia. 



This promised to be the proper mixture, and was what I then 

 called the Improved Superphosphate of Lime. Friends, and 

 others, who saw my crops, said, " As this mixture has such a 

 good effect on your land, I would like to try some of it." I com- 

 menced its manufacture in a barn thirty feet square, the mate- 

 rials being rolled on the floor with a garden roller, to break up 

 the parts, crush them, and mix them together. To-day the 

 manufacture requires a row of buildings, with a front certainly 

 as large as any New York block, with a 100 horse-power engine 

 to move the machinery. But some of my market gardening 

 friends, whose opinion I would rather have than that of farmers, 

 as they manipulate their grounds more severely, and require 

 larger results, said : " This manure acts well with us ; we get 

 larger crops from it than from stable manure, but it has a fault. 

 If we get our tomatoes in market ten days earlier, we get two 

 dollars a basket, while ten days later we get tAvo shillings. Now 

 if this mixture could only be made to be as early as our well 

 decomposed barnyard manure, as we use it in extraordinary 

 quantities, it would be a boon to us, because it costs us less than 

 barnyard manure, and at the same time does not carry weed seeds 

 to the soil." 



While this had been going on, I had been experimenting on 

 another matter in the same connection. A butcher, who lived 

 opposite me, killed many cattle, and being able to obtain the 

 blood in a fresh state, I found that one barrel of it mixed tho- 



