PHARMACY. 



would injure the product, a bent funnel 

 is necessary. It must be sufficiently 

 long 1 to introduce the liquor directly into 

 the' body of the retort ; and in withdrawing 

 it, we must carefully keep it applied to 

 the upper part of the retort, that the drop 

 hanging 1 from it may not touch the inside 

 of the neck. In some cases, where a 

 mixture of different substances is to be 

 distilled, it is convenient and necessary 

 to have the whole apparatus properly ad- 

 justed before the mixture is made, and we 

 must therefore employ a tubulated retort, 

 or a retort furnished with an aperture, 

 accurately closed with a ground stopper, 

 This tubulature should be placed on the 

 upper convex part of the retort before it 

 bends to form the neck, so that a fluid 

 poured through it may fall directly into 

 the body without soiling the neck. 



Retorts are made of various materials. 

 Flint-glass is commonly used when the 

 heat is not so great as to melt it. For 

 distillations which require excessive de- 

 grees of heat, retorts, of earthenware, 

 or coated glass retorts are employed. 

 Quicksilver is distilled in iron retorts. 



The simplest condensing apparatus 

 used with the retort is the common glass 

 receiver ; which is a vessel of a conical 

 or globular form, having a neck sufficient- 

 ly wide to admit of the neck of the retort 

 being introduced within it. To prevent 

 the loss and dissipation of the vapours to 

 be condensed, the retort and receiver 

 may be accurately ground to each other, 

 or secured by some proper lute. To pre- 

 vent the receiver from being heated by 

 the caloric evolved during the condensa- 

 tion of vapours in it, we must, employ 

 some means to keep it cool. It is either 

 immersed in cold water, or covered with 

 snow, or pounded ice, or a constant 

 evaporation is supported from its sur- 

 face, by covering it with a cloth, which 

 is kept moist by means of the descent of 

 water, from a vessel placed above it, 

 through minute syphons of spongy wor- 

 sted threads. But as, during the process 

 of distillation, permanently 'elastic fluids 

 are often produced, which would endan- 

 ger the hi* akin g of the vessels, these are 

 permitted to escape either through a tu- 

 bulature, or hole, in the side of the re- 

 ceiver, or rather through a hole made in 

 the luting. Receivers having a spot is- 

 suing from their side, are used when we 

 wish to keep separate the products ob- 

 tained at different periods of any distilla- 

 tion. For condensing very volatile vapours, 

 a series of receivers, communicating with 

 each other, termed adopters, were for- 



merly used ; but these are now entirely 

 superseded by Woulfe's apparatus, whicfi 

 consists of a tubulated retort, adapted to 

 a tubulated receiver. With the tubula- 

 ture of the receiver, a three-necked bot- 

 tle is connected by means of a bent tube, 

 the further extremity of which is im- 

 mersed, one or more inches, in some fluid 

 contained in the bottle. A series of two 

 or three similar bottles are connected witli 

 this first bottle in the same way. In the 

 middle tubulature of each bottle a glass 

 tube is fixed, having its lower extremity 

 immersed about a quarter of an inch in. 

 the fluid. The height of the tube above 

 the surface of the fluid must be greater 

 than the sum of the columns of fluid 

 standing over the further extremities of 

 the connecting tubes, in all the bottles or 

 vessels more remote from the retort. 

 Tubes so adjusted are termed tubes of 

 safety, for they prevent that reflux of fluid 

 from the more remote into the nearer bot- 

 tles, and into the receiver itself, which 

 would otherwise inevitably happen on 

 any condensation of vapour taking plac 

 in the retort, receiver, or nearer bottles. 

 Different contrivances for the same pur- 

 pose have been described by Messrs. 

 Welter and JJurkitt ; and a very inge- 

 nious mode of connecting the vessels 

 without lute has been invented by Citi- 

 zen Girard, but they would not be easily 

 understood without plates. The further 

 tubalature of the last bottle is commonly 

 connected with a pneumatic apparatus, 

 by means of a bent tube. When the whole 

 is properly adjusted, air blown into the 

 retort should pass through the receiver, 

 rise in bubbles through the fluids con- 

 tained in each of the bottles, and at last 

 escape by the bent tube. In the re- 

 ceiver, those products of distillation are 

 collected which are condensable by cold, 

 alone. The first bottle is commonly filled 

 with water, and the others with alkaline 

 solutions, or other active fluids ; and as 

 the permanently elastic fluids produced 

 are successively subjected to the action of 

 all these, only those gases will escape by 

 the bent tube which- are not absorbable 

 by any of them. 



In separating permanently elastic fluids 

 or gases from the substances in which 

 they are found, we are compelled to em- 

 ploy a distinct pneumatic apparatus ; and 

 the gas may then be received either into 

 vessels absolutely empty, or filled with, 

 some fluid, on which it exerts no action. 



The first mode of collecting 1 gases may 

 be practised by means of a bladder, mois- 

 tened sufficiently to make it perfectly 



