GUANO. 45 



le material used were, one lb. of guano to one gallon of water, 

 nd almost a wine-glass of the solution poured around each plant. 

 I solution a little stronger than this, destroyed some of the toma- 

 bes. It will be seen that those who have been in the habit of 

 ising a shovel full of manure to a hill of corn or potatoes, would 

 lery likely fall into a fatal error, in the use of this substance, by 

 jccessive doses ; and from facts in our possession, we are confi- 

 ent acres of corn have been destroyed in this way. 

 I The belief has been expressed by some, that there was guano 

 lOugh in the world that could be obtained, to supply all demands 

 or a thousand years at least. This, so far from being true, a little 

 llection will show that a few years, at the present rate of its use, 

 |ill serve to exhaust all deposits known of this substance ; and, of 

 lurse, from its source and well known mode of production, can 

 ver be renewed so as to form, hereafter, an article of commerce. 

 I Our farmers, then, will direct their attention to other sources of 

 janure, to supply the wants of their farms, and will not expect, 

 I least, to obtain it in any considerable amount, after one or two 

 ■a;s at farthest. 



HOW PLANTS ABSORB CARBONIC ACID. 



BY WM. PARTRIDGE. 



iThe first number of the American Quarterly Journal, contains 

 ?' article by Thomas Hun, M. D., on the food of plants, wherein 

 1 quotes Liebig, page 15, as follows — " the great value of the soil 

 k vegetation, depends on its earths and alkalies, which seem to 

 jpply the inorganic constituents of plants. The humus or mould 

 ijComparatively unimportant, except at certain stages of vegeta- 

 tjn, in furnishing carbonic acid to the roots." 

 Again, p. 17, 18 — " Carbonic acid is derived from the soil, 

 "Mere it is generated by the decomposition of vegetable matter, 

 .£i from the atmosphere. The main source of carbonic acid, is, 

 Ijwever, the atmosphere. How can this be otherwise, when the 

 .€prraous quantities of carbon which trees, the growth of centu- 

 Js, for example have laid up, are contrasted with the very limit- 

 € extent to which their roots extend. Very certainly where the 



