FIXING AND PRESERVATIVE MEDIUMS 6i 



gradually conducted into the jar by means of a thread acting 

 as a siphon. The thread ought to be of such a thickness as to 

 be capable of carrying over the whole of the solution of nicotin 

 in twenty-four hours." 



A method of narcotisation by means of tobacco-smoke is 

 thus described by Lo Bianco (pp. 449, 450) : — 



Such a sea-anemone as Adamsia rondeletii, found upon shells 

 tenanted by the large hermit-crab, is narcotised in the following 

 manner. The object on which the anemone is iixed is 

 suspended by a string from a small piece of wood supported 

 upon the edges of a vessel containing sea-water. The animal 

 is thus maintained perfectly extended without its tentacles 

 touching the sides before commencing operations. One or 

 many of these vessels are placed within a pan half filled with 

 water, and this is covered with a bell-glass, which fits within 

 the pan with its edges under water, so contrived, however, as 

 to allow a tube to pass under from the outside, curved in such a 

 manner as to come above the water of the pan. Through this, 

 strong tobacco smoke is blown by means of a special apparatus 

 until the bell-glass is filled with thick heavy fumes, the air being 

 allowed to escape through a second tube, curved in the form of 

 U, which is also passed beneath the edge of the bell-glass. To 

 regulate the duration of narcotisation it is necessary to make 

 the first fumigation towards the evening. Little by little the 

 fumes commence to dissipate, and the water commences to 

 absorb the narcotic, and the animals extend for the most 

 part their crown of tentacles. Three hours afterwards a second 

 fumigation is made, and the whole is left until the following 

 morning, when the glass cover is removed with care, and the 

 tentacles are touched with a needle to note their state of 

 sensibility. If they contract, a third fumigation is made, and 

 the tentacles are tried again with the needle after some two 

 hours. When insensibility sets in, a small open tube containing 



