6 4. HOW TO W< -RK 



< !!, next, from each side of this piece of glass, a strip of the required 

 \vidth is to be removed, and from its ends, corresponding strips are to 

 be cut off. The central portion is taken away, and the strips thus cut 

 out are inverted upon the slide upon which they are to be fixed with 

 marine glue, care being taken to mark them in the first instance, so that 

 they may correspond properly with each other. The marine glue is 

 allowed to run well into all the corners. In this way a capital cell 

 is very easily and quickly made. Cells of various sizes and depths 

 can be manufactured upon this principle. The surface of the glass 

 rim should be ground upon the stone, and the superfluous glue 

 removed in the ordinary manner. 



127. Small Deep Cells for Injections. By drilling a hole in a piece 

 of plate glass, by cutting off sections of various thickness from thick 

 glass tubing, or from thick square glass bottles, or from vessels moulded 

 for the purpose, excellent cells of various dimensions, and admirably 

 adapted for mounting injections and other purposes, are made ; but 

 when the preparation is of considerable thickness, deeper cells than 

 any of those to which I have alluded will be required. These may 

 be made in glass, gutta percha, and some other substances. A 

 round or oval concavity may be ground upon the surface of a piece 

 of very thick plate glass. Different forms of small deep glass cells 

 are represented in pi. XVII, figs. 101 to 105. Moderately deep glass 

 cells may be made also by grinding holes of the size required through 

 thick plate glass, fig. 105. 



128. Built Glass Cells are those which are constructed by joining 

 together, at the edges and ends, separate pieces of glass with marine 

 glue or some other cement. The simplest form of built glass cell has 

 been already described. 



Good cells may be made from thick plate glass, the edges of 

 which have been ground perfectly flat before they were united with 

 the marine glue. Dr. Goadby used to make many of these cells, 

 upon this principle of very large dimensions. They may be obtained 

 of Mr. Dennis, of St. John's Street Road, who has succeeded in 

 making plate glass boxes in this manner large enough to hold 

 several quarts of fluid. Many cells of this description may be seen 

 in the Hunterian Museum of the Royal College of Surgeons. They 

 may be constructed as follows : A strip of plate plass is cut off, of 

 the proper height for the sides of the cell. From this, two pieces are 

 to be cut off the desired length of the sides, and two pieces for the ends. 

 The flat surface of these are to be cemented with marine glue, and all 

 the edges ground perfectly flat together. The ends are also to be very 

 carefully ground square. They are then to be separated by heat and 

 connected together at the corners in the proper position, pi. XVIII, 



