170 APPENDIX. 



tagious, is sufficiently proved by the fact that it can at pleasure be in- 

 oculated on the soundest seed-corn. The infection, however, is not 

 so generally nor so readily communicated as the diseases occasioned 

 by the fungi of the smut-balls or dust-brand, a few infected ears of 

 which are capable of contaminating and affecting the whole contents 

 of a barn. Grains infested with these embryos cannot vegetate and 

 produce again diseased grains themselves, but can only communicate 

 the infection by coming in contact with the germinating seed-corn in 

 the soil, by the moisture of which the worms are revived, and extricate 

 themselves, which I have so often observed they do when kept some- 

 time in water. Steeping the seed-corn in lime-water, in the same 

 manner as advised for preventing the diseases occasioned by the fungi, 

 is the most efficacious method of preventing the spreading of this dis- 

 ease. I have repeated the experiment by inoculating, very strongly, 

 sound wheat-grains with the worms, and afterwards steeping them in 

 lime-water; and the affection was always prevented. I have, also, 

 steeped some sound wheat-grains in lime-water ; and after having kept 

 them in a dry state for some days, I inoculated them strongly with the 

 worms; but on examining the plants, not one instance of the affection 

 occurred. From these facts it is evident, that properly steeping the 

 seed-corn in lime-water before sowing, is a sure preventative of the 

 disease occasioned by the grain-worms." 



[H.] 



On Artificial Manure. 



Lowell, March 6, 1839. 



I. — Letter from S. L. Dana, M. D. 



Dear Sir, — The first letter which I write to you, was penned at sev- 

 eral sittings — for my head was so very bad, that I was often obliged to 

 throw down my pen and busy myself for hours in darkness. This is 

 my apology for the patchwork I sent you. I kept no copy. In the mean 

 time to make the most of the present letter, I send you the following 

 recipe for a top-dressing, which 1 think will be next best to " Flanders 

 manure," Give it to the farmers, either through the N. E. F. or at 

 your agricultural meeting to-morrow, or in both ways, or in any way 



