STORAGE JARS 365 



at Plymouth. The cork disc inside the cap is removed, 

 and a disc of rubber, punched to the exact size of the 

 cap, is fastened in the place of the cork. 



Glass Jars with Glass Caps. — These jars are used for 

 preserved fruits in syrup, and are the best jars to take 

 on collecting expeditions. The cap is a glass disc with 

 a projecting rim, which rests upon a rubber ring fitted 

 on the neck of the bottle. There are several devices for 

 holding down the glass cap, and it would be difficult to 

 say which is the best. The jars are more costly than 

 those with metal caps, and run in larger sizes, from 

 1 to 4 pounds (1,800 c.c). An excellent jar in the 

 series is known as the " Apricot " jar, which is a squat 

 2-pound jar (1,000 c.c. capacity), with an extra large 

 mouth. 



The common " sweetstuff " jar, with a glass stopper, 

 to which is fitted a cork rim, is not recommended for 

 travelling purposes. These jars are not intended for 

 fluids, and usually leak. The cork strip cracks easily, 

 and the stoppers are difficult to raise. 



For large specimens stoneware tobacco- jars, with 

 extra wide mouth, which have a top that can be 

 screwed down on a rubber ring, are very convenient. 

 They can be obtained in several sizes. 



For collecting expeditions jars fitted with rubber 

 discs can be recommended, and for storage special 

 wooden boxes should be made, fitted with partitions 

 for the isolation of each bottle, and the bottom and 

 partitions and the inside of the lid lined with thick 

 felt. With these boxes the jars are always ready for 

 use ; there is no unpacking or packing up. 



Glass Tubes with Cotton- Wool Plugs. — This method is 

 often used for the isolation of specimens in small tubes, 

 and it can be thoroughly recommended. The tubes 

 are tightly plugged with absorbent cotton-wool, in- 



