274 VII. EARTHS AND ALKALIES.— 



filter. --Henri/s carbonate ofpotasse water, is made up to the spec, 

 grav. of 1 'SlS, that it may saturate an equal measure of sul- 

 phuric acid, spec. grav. 1*135, or of nitric acid, spec. grav. 1*143, 

 or of muriatic acid, spec. grav. 1074. Used in assaying mineral 

 waters. 



Bicarbonate of potash, Kali a^ratum^ Potasses carhonas^ 

 P. L. 18!<J4. Dissolve subcarbonate of potash lib., in water 31b., 

 and pass through the liquor the gass expelled by adding pounded 

 tnarole to dilute sulphuric acid ; the carbonate of potash crystal- 

 lizes as fast as it is formed : preferable, as being milder tasted 

 than the subcarbonate ; used to form effervescent mixtures. 

 Composed of 6 potash, 5-5 carb. acid, and 1*125 water; equiv. 

 2*6^25. Use the same as that of the Subcarbonas potassoe already 

 noticed. 



2. Dissolve pearl-ash in water, add bran, or saw-dust, to soak 

 up the liquor, put it into a crucible, cover, lute the joint, and heat 

 the crucible till it is red hot. When cooled, wash out the salt, 

 evaporate and crystallize, until no more crystals can be obtained ; 

 then heat the remaining liquid with fresh bran, and proceed as 

 before. 



Lixivium saponarium, Pure potash water, Solution of potash 

 prepared with lime, Eau seconde. Aqua kali puri, Liquor potasses^ 

 Upon quick lime 5vj, pour boiling distilled water lb. vj, and add 

 subcarbonate of potash lb. j, dissolved in water 21b. : cover the 

 vessel, and when cool filter through cotton cloth ; if it effervesce 

 with a dilute acid, it must be treated again with fresh lime. A 

 pint should weigh exactly 3xvj ; if it weigh more, for everjr 

 drachm of excess add 3ss of distilled water to each lb. Troy ; if 

 less, evaporate some part of it. Used in calculous complaints. 



AauA KALI cAusTici, Aqua potassos. Lime 8 oz., add water 

 24 oz., when cold add subcarb. pot. 6 oz.; strain, adding fresh 

 water, so as to get 36 oz. — Henrys pure potash water. Is made 

 up to the spec. grav. 1*1 ; two measures of it have the same 

 effective strength as one measure of his carbonate of potash water. 

 Used in analyzing substances. 



Potash prepared with alcohol. Evaporate a solution 

 of salt of tartar, nitre fixed by charcoal, or the white flux, made 

 caustic by quicklime, to the consistence of syrup, cool to about 

 130 degrees of Fahrenheit, add three times its weight of alcohol, 

 and keep for some days, draw off the clear, wash the bottoms with 

 fresh alcohol, and add to it the other. Distil off 2 oz. out of 3 of 

 the alcohol used, evaporate the remainder in a silver basin, taking 

 off the scum ; when nearly red hot, pour it out on a very dry 

 marble slab, or silver basin, and break it up as soon as it fixes,. 

 To be kept in small parcels, in very dry, well-stopped vessels. 



