INTRODUCTORY CHAPTER. xliii 



and July, when the leaves are full of sap, and are therefore, I 

 should imagine, more productive of the alkali than when they 

 begin to fade and shrink.* 



Being desirous of knowing how much alkaline salt was pro- 

 duced from a given quantity of the salsola, and the comparative 

 produce of alkali from furze and blackberry bushes, Doctor Kay, 

 the medical superintendant, obligingly undertook the experi- 

 ments, and reported as follows : 



" From a trial I made, to find liovv much salt a given quantity 

 of the plant supposed to be the salsola would produce by inci- 

 neration, and also to ascertain the comparative quantity to be 

 obtained from the stems, and leaves separately, the results were 

 as follow : 



No. 1. Thirty-eight pounds of the plant burnt 



entire (under cover) yielded of dry marine alkali, oz. 



or impure soda -____- 19 



No. 2. Eighteen pounds of the stems entirely di- drachms. 

 vested of leaves, yielded of the same salt, - 10 



No. 3. Thirty-one pounds of leaves adhering to the oz. 



small extreme branches, yielded _ - _ igl 



Three pounds of the large stems were burnt with the leaves 

 in order to begin and support the ignition ; but according to 

 No. 2, the salt from these stems would only be 1 drachm and 2 

 scruples, so that the salt from the leaves was 16|- ounces and 1 

 scruple. Therefore, 100 pounds of leaves will produce upon an 

 average 3 pounds 5:|- ounces of salt nearly. And the entire plant, 

 by trial No. 1, will produce only 3 pounds 2 ounces. But, a day 

 or two after the lixivium No. 1. had been evaporated, 1 found as 

 much remaining in the cask from which it had been drawn as 



* The leaves of the salsola are small ; linear ; sliort (| inch) ; rounded, and flesliy : 

 although full of sap, the plant burns fiercely without being dried. (See Appendix — 

 Salsola salsa.) 



