434 Botanical Society of Edinburgh : — 



BOTANICAL SOCIETY OF EDINBURGH. 



April 9, 1857. — Professor Balfour, Vice-President, in the Chair. 

 The following papers were read : — 



1 . " On the Effects of a Solution of Bicarbonate of Ammonia in 

 promoting Vegetation," by C. J. Burnett, Esq. 



The author stated, that the carbonate of ammonia had been recom- 

 mended as existing in the refuse-liquor of gas-works, on account of the 

 comparative cheapness of the ammonia in this form, but that he was in- 

 clined to recommend the carbonates of ammonia also on other very im- 

 portant grounds ; viz. — that the compound of ammonia with carbonic 

 acid was the most natural of all the ammonia manures, and that, in con- 

 verting it into the sulphate and other salts commonly sold for ma- 

 nure, we drive off a most important element of plant-food, of much 

 more universal value than the sulphuric or other acid by which it was 

 replaced. For healthy growth, a proper proportion of carbon should 

 accompany the nitrogen added ; and we should not attempt to dis- 

 sever those substances which Nature had shown such an evident 

 desire to associate in their application to plants. Instead of driving 

 off the carbonic acid, he would recommend adding more of it, so as 

 to convert the monocarbonate, or mixture of carbonates, into a more 

 fixed and more nutritious bicarbonate. Till a cheap form of bi- 

 carbonate, corresponding to the other agricultural salts, should be 

 in the market, a solution of the proper nature might be easily and 

 conveniently made by any one, by saturating with carbonic acid 

 evolved from muriatic acid and chalk or limestone a solution of the 

 common carbonate, or perhaps the common gas-liquor. The manu- 

 facture was one which any farmer or gardener could readily carry on 

 with two barrels and a bent piece of lead tube ; and the solution 

 might be carried to the field in barrels, and applied by a rose or 

 pierced tube. The solution should be very dilute when applied. 



To make more clear the particular object for which he now recom- 

 mended the use of this manure, he would say a word or two on the 

 different natures and applications of manures in general. They 

 might be divided into two classes: — 1st, Manures which afforded 

 ingredients of plant-food which could be supplied by the soil alone ; 

 2nd, Manures which supplied ingredients which were also contained 

 in the ?lir. As to the first class, whether (as in the majority of in- 

 stances) required during the whole period of plant-growth, or merely 

 in its latter stages (as phosphates in case of corn crops, &c.), they 

 should be added in a quantity sufficient for one crop at least, and in 

 a sparingly or gradually soluble form, to prevent serious loss from, 

 their being washed down out of reach of the roots. As to the second 

 class, however, the case was very different indeed. Though the 

 carbon and nitrogen which they supplied were essential elements of 

 plant-food at every stage, yet, as it was only in the earliest stages 

 that the earth was their only source, and as it was manifestly bad' 

 economy to pay money for what you could have for nothing, the 

 use of manure of this class should be principally confined to the' 



