On the Preservation ofAnimcds in Fluids. 165 



softened by contact with the alcohol, and allows the latter to 

 evaporate. The following preparation has been used with more 

 success. It consists in soaking the cork for some time in a 

 composition of three parts of wax and one of tallow, kept fluid 

 by a moderate heat. It is then covered with a flexible envelope, 

 which penetrates its pores and prevents evaporation. The stop- 

 per is also sometimes covered with a mastich made of four parts 

 of pitch, one part of sulphur, and a half part of tallow, well melt- 

 ed together. This covering is applied hot. Dr Sue employed 

 the following method : He placed a round plate of glass on the 

 mouth of the bottle, put a piece of oiled parchment over it, 

 covered the parchment with a bit of sheet-lead, over which he 

 applied a second piece of parchment soaked in oil coloured with 

 lamp-black. He then tied the whole with a small cord as tightly 

 as possible. 



The following are the means recommended and employed by 

 Peron, — to prefer cork-stoppers to glass-plates, which are easily 

 broken, and to employ a luting easily made, instantaneously dry- 

 ing, and capable of resisting the shocks given by the rolling of 

 tli^ vessel, as well as the evaporation of the alcohol. This luting 

 consists of common resin, red ochre, yellow wax, and oil of tur- 

 pentine, in variable proportions, according as the luting is wish- 

 ed to be hard or soft. The manner of preparing it is as follows : 

 The resin and wax are first melted ; the ochre is then added in 

 small quantities ; the mixture is well stirred with a spatula, 

 and the whole allowed to boil for seven or eight minutes. The 

 turpentine is then added, and the boiling allowed to go on. 

 To obviate the danger of the mixture taking fire, a vessel is 

 used capable of containing at least three times the quantity, and 

 furnished with a handle, so that it may be easily taken off. 

 Should the substances happen to take fire, the vessel is to l>e 

 covered with a lid made of wood, tin, or copper, by which the 

 flame will be instantly extinguished. 



This luting is employed as follows : The cork is exactly fitted 

 to the aperture, which is wiped dry with a cloth ; the luting is 

 heated to a degree approaching to ebullition ; a coarse brush is 

 made with a piece of linen ; the mixture is stirred to prevent 

 the ochre from sinking to the bottom, and a little of it taken up 

 with the brush and applied upon the outer surface of the cork. 



