422 [Senate 



consider that soils consist of bases, oxides, salts, constant in their 

 nature and incapable of change in themselves, we must turn our at- 

 tention to those elements in nature which act upon these bases. If 

 these bases were kept in a dry state, there would be no change in 

 them, it is only when acted upon by other elements that they unite 

 in any vegetable or other product. It is then to the active elements 

 we must look for causes. There are in constant play in the ocean of 

 air, light, gases, electricity, &c. &c. operating upon the surface of 

 the earth, and their effects are found to be for all our purposes con- 

 fined to about one foot in depth on the earth, that being the average 

 depth of soil. 



A singular occurrence has lately been noticed by chemists, that is 

 the presence of caseine in diseased potatoes. Caseine is very perish- 

 able, whereas starch which constitutes the valuable element of the 

 potato is not so, for it may be extracted pure from rotten potatoes. 



Solanin has lately been adverted to. It seems that this poison, of 

 which a trace is always to be found in the solanum tuberosum (potato) 

 is found to be much more abundant in the stalk of potatoes grown in 

 cellars where there is but little light ! 



Question fourth. — Were any means of preventing the recurrence 

 of the potato disease in successive years found effectual. 



I reply, that I have no confidence, for any useful purpose in any 

 of the theories yet published. We all know that there are epidemics 

 occasionally, both in the animal and vegetable kingdom, (if the word 

 may be applied except to people,) which baffle all our knowledge 

 both as to their beginning and end. One truth, however, remains 

 for our consolation, and that is that they are. if periodical, not very 

 lasting. The animals and plants still continue to grow, although dis- 

 astrous interruptions occur in their progression. The original potato 

 still keeps its annual growth in wild places in South America, some- 

 times among the wild cacti in barren places, annually yielding its 

 little tuber somewhat ot the form and size of a pea-nut, putting forth 

 annually its little seed ball, which again falling to the earth renews 

 the seedling potaio from age to age. Perhaps it would be well for 

 us, (as I have long ago suggested,) to procure these wild originals, 

 and by careful culture in our gardens, obtain a new race, which may 

 remain domesticated, and feed us for another period of three centu- 

 ries. I have sent to South America for them, and hope that the ex- 

 periment will be fully tried. We have long ago tried seedlings and 

 obtained great varieties. But perhaps the seedling from the domes- 

 ticated race may not possess the stamina of the wild original which 

 has maintained its character from creation. 



Accept, my dear sir, upon this vexed and important question, the 

 answers here given to your four questions. I have said thus much, 

 not having found the lost gem, but because I believe that in a multi- 

 tude of seekers it may be found. 



I have the honor to be, with great esteem and consideration, your 

 obedient servant. 



HENRY MEIGS. 



