TREATMENT OF SNAKES IN CAPTIVITY. 67 



bent upwards at a right angle and closed by a screw, at the 

 uppermost border of the opposite end. Over the former a piece 

 of india-rubber tubing is fixed when it is to be emptied, to pre- 

 vent splashing ; while a funnel can be inserted into the other to 

 facilitate the process of filling. And since this operation in- 

 volves no inconsiderable amount of trouble, it is extremely 

 desirable that the heat should be economised and expended 

 entirely in the right direction, viz., to warm the cage as far as 

 possible. We must endeavour, therefore, to absolutely prevent 

 its evaporation from any surface except the upper by encasing 

 the other five sides of the reservoir in thick non-conductive 

 material. The one of which I write is "packed" in a complete 

 envelope of felt an inch thick, which is adherent to the metal 

 through the medium of a glue-like cement ; holes are cut for the 

 two pipes, which are the only exposed points, and caps are made 

 to fit over even these. Underneath, on the top of the stand, an 

 extra bed of felt is laid, and the sides are covered with green 

 cloth for neatness of appearance. It is extraordinary to note 

 how very long this preserves the caloric, considering how lightly 

 the upper surface is defended from radiation ; but I may remark 

 here that a depth of nine inches is hardly sufficient for a floor of 

 this extent. It would save time and trouble to allow a foot, for, 

 though the capacity of the tank would be thereby greatly in- 

 creased, it would require filling much less frequently. The 

 intervals at which the water should be renewed will, of course, 

 depend upon the situation of the apparatus, and the partial or 

 complete covering of the glass and top ; and on the capacity of 

 the cistern, out of all proportion to its relative size. Six gallons 

 of water will retain heat ten times as long as two, under similar 

 conditions. The owner must be guided by the indications of his 

 thermometer ; such a cage as I refer to requires to be replenished 

 every three days with full exposure in the ordinary temperature 

 of a living-room, but with the cover on would keep warm a week. 

 It should always be quite full, and the water should be as near 

 the boiling-point as possible when it is poured in ; a very gradual 

 diminution of the heat may be insured by withdrawing a quantity 

 — say a large kettleful — morning and evening, and at once 

 replacing it with boiling. Every particle of heat must be 

 hoarded, and, as undue waste can be prevented with attention to 

 these few details, which are simple enough after once being 



