Preparing of the Bodies ofAnimaU, 379 



together then placed in alcohol. Nor must I forget to mention, 

 that the examination of very delicate organizations may fre- 

 quently be conducted with greater facility and accuracy, if the 

 objoct be previously allowed to remain some time in ftpirit«, ajM) 

 thereby to become harder and contracted. This applies parti* 

 cularly to the dissection of nervous organs, and to the examioa* 

 tion of very small embryos, of moUusca, and wonns. 



Tliere are various modes of destroying worms, insects, raoU 

 hisca, &c. for the purpose of dissecting, without injiuring their 

 organization : MoUusca, snails, for instance, as Swammerdam 

 has remarked, are to be allowed to die in water, because by that 

 means tlieu* body swells, and all the parts become more dis» 

 tinctly visible ; they may afterwards be kept in spirit (though 

 not too long) for dissection. Worms, the larger zoophytes, 

 (for the smaller must be examined whilst alive), caterpillars, &a 

 and also the smaller amphibia and fishes, are best destroyed by 

 means of spirit : Insacts, on the contrary, by being dipped nu 

 pidly in boiling water, or in oil of turpentine. 



As regards the dissection of larger animals, we may here use 

 with advantage knives of a large size, and insteajd of forceps, 

 suitable hodis with handles. 



In animals of considerable size we can generally make artlfi- 

 ci^ skeletons only, after the bones have been sufficiently clean- 

 ed by boiling or maceration. In smaller animals, on the ooa> 

 trary, such as birds, amphibia, and fishes, of which last it is 

 very difficult to make good skeletons, the object will be best ac- 

 complished by at once making the bones as clean as possible, 

 without injuring the capsular ligaments, soaking the preparation 

 in water that is incessantly changed, and, lastly, bleaching it for 

 some time in tlie sun. 



Lastly, we may mention injections as affording a very essen- 

 tial assistance in zootomical investigations for physiological pur- 

 poses : in small animals, and in the more minute parts, these 

 must consist of compositions with wax, very fluid and coloured; 

 but above all of mercury. The latter, however, is not suitable 

 for very soft bodies, e. g. medusae, &c. in which cases we may 

 employ injections of coloured milk, and similar substances. 



