In Mr. Chivers's note on Preserving Animals, No. 117 of 'Science-Gossip,' the following passage occurs:--"The skeleton must be put in an airy place to dry, but not in the sun or near the fire, as that will turn the bones a bad colour." I cannot comprehend how this idea should have arisen. Perhaps the most indispensable assistant to the skeleton preparer is that very sun which Mr. Chivers warns him against. The bleaching power of the rays of a hot summer sun is astounding, and bones of the most inferior colour can rapidly be turned to a beautiful white by this means. It is for want of time and care in following out this method that the professional skeleton preparers in London resort to the aid of lime, which, although it makes them white, is terribly detrimental to the bones themselves. In a smoky city like London, the principle of sun-bleaching would be hard to follow; but so great is its value, that more than once I have had valuable specimens sent down to me in the country, by a comparative anatomist in London, to undergo a course of sun-bleaching; and a specimen which I have received stained and blotched, I have returned of a beautiful uniform white, a change entirely due to that sun which we are told to beware of. The question, How are skeletons to be prepared? is one which is repeatedly asked. People desire a method by which with little trouble the flesh may be removed from a specimen, and a beautiful skeleton of ivory whiteness left standing in its natural position. I can assure all such inquirers that this cannot be accomplished by any method at all. The art of preparing bones is a long, elaborate, and difficult one, and he who wishes to become a proficient in it must be alike regardless to the most unpleasant odours, and to handling the most repulsive objects. Mr. Chivers's receipt for the maceration of specimens is about the best which one could have, only I should not advise so frequent a change of the water. What is needed is as rapid a decomposition of the flesh as is possible, and then the cleaning of the skeleton just before the harder ligaments have also dissolved. But this requires very careful watching, and with the utmost pains it is almost impossible to get a skeleton entirely connected by its own ligaments.