Methods of preparing Natural Skeletons of Birds. 55 



in question was in immature winter plumage, I could not deter- 

 mine the species. 



87. Larus audouinii, Temm. Audouin's Gull. 

 Gould's Birds of Europe, vol. v. pi. 438. 



On two or three occasions, at a considerable distance above 

 Cairo, I noticed a large Gull with a bright red bill, which I be- 

 lieve to have been Larus audouinii. I never succeeded in pro- 

 curing a specimen. 



IV. — On the different Methods of preparing Natural Skeletons 

 of Birds. By T. C. Eyton, F.Z.S., &c. 



I PROPOSE in this paper merely to state the different methods 

 which I have employed in preparing the natural skeletons in my 

 collection. Not that I entirely object to artificial skeletons ; but 

 I prefer natural, particularly if purchased from dealers, as the 

 former are so very liable to be adulterated, if I may so apply the 

 word. I have now before me a beautifully mounted skeleton of 

 a Circus, purchased of a dealer, which has two left metatarsi. 



Birds generally come into collectors^ hands either fresh with 

 the flesh on, or partially cleaned and without having been 

 macerated, or partially cleaned and having been also macerated. 

 In the first case, I always remove as much of the flesh as I con- 

 veniently can, and macerate the skeleton in water, which has a 

 small piece of the flesh, previously removed, placed in it, until 

 the flesh which remains on the bones becomes soft and easily 

 scraped off. After this I place the skeleton in clean water, and 

 change the water frequently until it ceases to become discoloured. 

 I then place the skeleton in a solution prepared in the following 

 way : — Make a saturated solution of common alum, and when 

 cool dilute it with an equal quantity of water, and add to it half 

 an ounce of common salt for every half-pound of alum. This 

 solution converts the ligaments into a species of leathery sub- 

 stance, and also destroys the colour of any blood that may have 

 penetrated the bones. The time that is required to effect this 

 varies according to the state and size of the skeleton. If it be 

 clear of blood, twenty-four hours will be sufficient ; but some- 



