SALSOLA KALI. ORD. XL. Oleracee. 653 
It is to be regretted, that the different kinds of Soda which are 
brought to European markets, haye not been sufficiently analysed 
to enable us to ascertain with tolerable certainty the respective 
value of each; and indeed while the practice of adulterating this 
salt continues,*any attempts of this kind are likely to prove 
fruitless: the best information on this subject is to be had from 
Jussieu,® Marcorelle,' Cadet,* Borlase,' and Sestini.™ In those 
places where the preparation of Soda forms a considerable branch 
of commerce, as on the coast of the Mediterranean, seeds of the 
Salsola are regularly sown in a proper situation near the sea,” 
which usually shoot above ground in the course of a fortnight. 
About the time the seeds become ripe, the plants are pulled up 
by the roots, and exposed in a suitable place to dry, where their 
seeds are collected: this being done, the plants are tied up in 
bundles, and burned in an oven constructed for the purpose, 
where the ashes are then while hot continually stirred with long 
poles. The saline matter, on becoming cold, forms a hard solid 
mass, which is afterwards broken in pieces of a convenient size for 
exportation. 
According to chemical] analysis Soda generally contains a portion 
of vegetable alkali and neutral salts, as common salt, and sometimes 
vitriolated tartar, or Glauber salt, likewise-trver of sulphur, and not 
unfrequently some portion of iron is contained in the mass; it is 
therefore to be considered as more or less a compound, and its 
goodness is to be estimated accordingly. The Spanish Soda, of the 
best sort, is in dark coloured masses, of a bluish tinge, very 
‘ af, 
raw t k Vide Mem. de ? Acad. &c. 1767. p- 387. 
‘ee 
™ Lettre della Sicilia, tom. 3. p. 58, 76. 
" According to the experiments of Du Hamel, the further from the sea the seeds 
are sown, the less fossil alkali, and the more vegetable alkali si plants contain. 
Vide Med. de ? Acad. 1767. p- 233. 
No. 50.—vo1. 4. 8c 
