PHARMACY. 



distillation be carried on to any great 

 length, it is extremely difficult to avoid 

 empyreuma. The best method of pre- 

 venting this inconvenience is, if a retort 

 be used, to place the sand but a little way 

 up its sides, and when somewhat more 

 than half the liquor is come over, to pour 

 on the remainder a quantity of fresh vine- 

 gar equal to the liquor drawn off. This 

 may be repeated three or four times ; the 

 vinegar supplied at each time being pre- 

 viously heated. The addition of cold li- 

 quor would not only prolong the opera- 

 tion, but also endanger the breaking of 

 the retort. 



Lowitz recommends the addition of half 

 an ounce of recently burnt and powdered 

 charcoal to each pound of vinegar in the 

 still, as the best means of avoiding empy- 

 reuma. 



If the common still be employed, it 

 should likewise be occasionally supplied 

 with fresh vinegar, in proportion as the 

 acid runs off, and this continued until the 

 process can be conveniently carried no 

 further. The distilled acid must be rec- 

 tified by a second distillation in a retort 

 or glass alembic ; for although the head 

 and receiver be of glass or stone ware, the 

 acid will contract a metallic taint from the 

 pewter worm. 



Tiie residuum of this process is com- 

 monly thrown away as useless, although, 

 if skilfully managed, it may be made to 

 turn to good account, the strongest acid 

 still remaining in it. Mixed with about 

 three times its weight of fine dry sand, 

 and committed to distillation in a retort, 

 with a well-regulated fire, it yields an ex- 

 ceedingly strong empyreumatic acid. It 

 is, nevertheless, without any rectification, 

 better for some purposes, as being strong- 

 er than the pure acid ; particularly for 

 making acetate of potash or soda : for 

 then the empyreumatic oil is burnt out. 



Distilled vinegar should be colourless 

 and transparent. ; have a pungent smell, 

 and purely acid taste, totally free from 

 acrimony and empyreuma, and should be 

 entirely volatile It should not form a 

 black precipitate on the addition of a so- 

 iution of baryte, or of water saturated 

 with sulphuretted hydrogen; or change 

 its colour when super-saturated with am- 

 monia These circumstances show that 

 it is adulterated with sulphuric acid, or 

 contains lead, copper, or tin. 



Distilled acetous acid, in its effects on 

 the animal economy, does not differ from 

 vinegar, and as it is less pleasant to the 

 taste, it is only used for pharmaceutical 

 preparations. 



CLASS II. Molina. ALKALINES. 



The following are the chief prepara- 

 tions under this head : 



Carbonas potassae, carbonate of potash, 

 prepared kali, mild vegetable alkali, salt 

 of tartar. 



Potassa, pure kali, caustic vegetable al- 

 kali. 



Potassa cum calce, lime with pure kali, 

 mild caustic. 



Aqua potassx, Edin. aq. kalipuri, Lond. 

 water of potash, caustic ley. 



Acetis potassae, Edin. acetite of potash, 

 acetated kali, Lond. 



Sulphas potassae, Edin. sulphate of pot- 

 ash, vitriolated tartar, vitriolated kali, 

 Lond. 



Sulphas potassae c- sulphure, Edin. sul- 

 phate of potash with sulphur, sal poly- 

 chrest, Lond. 



Sulphuretum potassae, Edin. sulphuret 

 of potash, liver of sulphur. 



Tartris potassae, tartrite of potash. Edin. 

 soluble tartar, tartansed kali, Lond. 



Carbonas sodae, carbonate of soda, Edin. 

 prepared natron, Lond. 



Phosphas sodze, Edin. phosphate of 

 soda. 



Murias sodae, muriate of soda, sea salt. 



Sulphas sodse, Edin. sulphate of soda, 

 natron vitriolatum, Lond Glauber's salt. 



Tartris sodae, Edin. tartrite of soda, na- 

 tron tartarisatum, Lond Rochelle salt 



Alcohol ammoniatum, Edin. ammoniat- 

 ed alcohol, spirit of ammonia, Lond. 



Carbonas ammoniae, Edin. carbonate of 

 ammonia, prepared ammonia, Lond. 



Aqua carbonatis ammoniae, Edin. water 

 of carbonate of ammonia. 



Aqua acetitis ammoniae, Edin. water of 

 acetile of ammonia, spirit of mindere- 

 sus. 



Hydro sulphuretum ammoniae, hj'dro 

 sulphuret of ammonia. 



Liquor volutilis cornu cervi, sal et oleum, 

 Lond. spirit oil, and salt of hartshorn. 



CLASS HI. Terrena. EAHTHS, AND 

 EARTHY SALTS. 



The following are the preparations 

 chiefly in use : 



Murias barytae, muriate of baryte, Edin. 



Aqua calcis, lime water, Edin. Lond. 

 Dubl. 



Carbonas calcis praeparatus, prepared 

 chalk, Lond. carbonate of lime, Edin 



Phosphas calcis, Edin. phosphate of 

 lime, burnt hartshorn, Lond. 



Carbonas magnesia:, Edin. magnesia al- 

 ba, Lond. Dubl! carbonate of magnesia. 



