THE SOCIETY S NOTE-BOOKS. 



41 



Fowl Flea, showing muscles all over the body, the large mus- 

 cles of the thorax and legs being particularly visible, was mounted 

 in the following manner : — It was killed with ether, and allowed to 

 soak in that medium for three to six days, then soaked successively 

 for a day at a time in water, methylated spirit, absolute alcohol, 

 and oil of cloves, and finally mounted in balsam. The process is 

 easy, and as a number of objects may be done at one time, there 

 is no real waste of time. Objects so prepared should be mounted 

 without pressure, which may be effected by allowing the cover-glass 



to rest on three fragments of thin glass. 



F. J. Allen. 



Cowrie Shell Section.— Hugh Miller, in that delightful book, 

 the " Testimony of the Rocks," dwells at some length on what he 

 calls the " human cast and character " of the contrivances which 

 the organisms of the geologic period exhibit, and familiar as I am 

 with every kind of mechanical and structural device in the dock- 

 yard, this idea is brought frequently before me with peculiar force, 

 and I could not help recalling it when looking at Mr. West's ex- 

 quisite drawing of the section of Cowrie shell, and the description 

 of it in the text. Every one knows that the framework of a ship 

 is composed, so to speak, of two elements, viz., the timbers or 

 perpendicular framing, and the horizontal planking laid there- 

 on as indicated by the upright and horizontal lines here shown — 



Fig. 



I. 



\ !Nr4NN\l44^ 



^^ssss 



L/ 



// 



but perhaps it is only those who 

 have opportunities of seeing the 

 thing who are aware that in many 

 of our ships of war, at all events, 

 the structure is further strength- 

 ened by diagonal tie-bars of iron | | | | |^ | 

 inside, as indicated by the lighter 



cross lines, which thus answer exactly to the interlacing diagonal 

 fibres of the Cowrie shell, as mentioned by Mr. West. See page 37. 



A. Hammond. 



Hantsch's fluid as a mounting medium, is a very valuable 

 one for many purposes ; it is composed of three parts alcohol, two 

 parts distilled water, one part glycerine. Its density approaches 

 closely to that of common water ; hence it may be used for mount- 

 ing the most delicate structures, as alg?e, &c., which by osmosis 

 become instantly spoilt by the action of pure glycerine. By repeated 

 additions, the alcohol and water evaporating, the specimen will 

 remain in glycerine alone. Of course it must be carefully protected 



