504 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XiX. 



into the box and the lid, and fixed with Bmall nails to the inner sides without 

 touching the joint faces. To attach the hinges the lid is put in place with a 

 heavy weight on it, and the hinges are attached with screws from the outside 

 A couple of hooks oa the opposite side keep the lid in contact with the box. 

 A careful workman can fit a lid of this kind sufficiently well to exclude all 

 dust, and diminish air leakage to a satisfactory extent. A small amount of 

 quicklime or other absorbent will preserve the contents of such a box for a 

 long period. In places where the white ant is troublesome a coating of 

 spindle (mineral) oil will give to wood such a bitter taste that no vermm will 

 touch it. This oil sinks in, but does not evaporate like kerosene. For 

 cabinets and show cases the process of Mr. Powell gives absolute security 

 against attacks by vermin. Examples of wood treated by this process 

 are on the table, along with a kerosene tin which fulfils all the duties 

 of a large drying bottle at a fraction of the cost. It is fitted like a coffee 

 canister but its peculiarity is a cap which fits tight without sticking. The 

 neck, standing up about li inches, is tapered, while the cap is parallel and 

 four inches deep. When pressed over the neck, the lid being elastic fits 

 closely all round with only a line of contact so that it cannot stick. A bag of 

 quicklime hangs within the lid to absorb moisture. Cartridges have been kept 

 ten years in such a box and used without a failure. The neck and cap may 

 be made 7 inches in diameter, admitting large articles. Lime should, when 

 possible, be put in ihe highest part of a dry box or case, as water vapour, being 

 only three-fifths of the weight of dry air, always rises. The lime thus esta- 

 blishes a circulation of air until all the water vapour is absorbed or the lime 

 becomes saturated. 



This tin although superior to many boxes is not so tight as it appears for. 

 when tested with the pressure gauge a pressure of three inches of water dis- 

 appears in a few seconds. It has nevertheless done excellent service. 



The following absorbents are used for drying the air in closed vessels. 

 Oatmeal, dried at 350 degrees F. chloride of calcium, quicklime, dried 

 sawdust, chloride of sodium or common salt, and sulphuric acid. Most of 

 these may be de-hydrated and used again. When any object or specimen is 

 placed, damp, in a box the lime or other absorbent may have to be changed 

 one or more times to bring the object to the required condition, after which 

 the duty of the absorbent will be to compensate the influx of moisture due to 

 changes of temperature or atmospheric pressure. 



The dampness of the air in any case or box may be observed with the aid 

 of a Sassure hygrometer which indicates moisture by the alteration of length 

 of a single hair that has been washed in pure alcohol to free it from grease. 

 If the case is large a small wet and dry bulb hygrometer may be used. A 

 certain but unknown amount of moisture may be tolerated in cases containing 

 natural history specimens, the amount depending on the temperature of the 

 air. Absorbents are of very little use in an ordinary cupboard or almirah 

 during wet weather. The joints of the doors and framing offer an easy 



