8 



HARDWICKE'S SCIENCE-GOSSIP. 



[Jan. 1, 186S. 



black races — a privilege which might have been 

 claimed with equal right by the old countryman who 

 ascribed the rising of the Goodwin Sands to the 

 building of Tenterden steeple. He tells us that 

 some untenable views which he puts forward, prove 

 the necessity for a theory which insists upon the 

 acknowledgment of the Unity of Mankind, un- 

 conscious what a scathing censure he thus passes 

 upon his own mode of reasoning ; and winds up by 

 congratulating himself upon having demolished 

 " R. G." and Mr. Milton ; forgetting that no one 

 has constituted him judge in his own cause, and 

 that he has laid his case before the readers of 

 Science-Gossip, to whose fiat he must bow. 



I decline to follow " F. A. A." in his attempts to 

 connect his theory with revealed truth. I am quite 

 of " R. G.'s " opinion, that such matters should not 

 be imported into scientific discussions. 



J. L. Milton. 



HOW TO PRESERVE SPIDERS. 



A CORRESPONDENT in Science-Gossip, in 

 the November number, signing himself 

 "B. W. S.," asks the best way of preserving 

 spiders, so as to retain their beautiful colours, and 

 prevent their shrivelling up. As I was very suc- 

 cessful in my attempts, perhaps the method I 

 adopted more than forty years ago, while residing in 

 the Isle of Prance, may help him. 



Before answering his question, however, I may 

 mention what I fancy is not generally known, or, if 

 known, not attended to, that the colouring matter 

 or pigment is placed between the outer or ab- 

 dominal covering, and the pulpy contents within, 

 upon a very delicate membrane, which adheres very 

 loosely to both, but more firmly to the contents 

 within; so that when the viscera or [contents are 

 rudely removed, and without much tearing, the 

 whole mass will be found more or less coloured, 

 while the outer skin will be left entirely transparent. 

 If your correspondent is an anatomist, it will strike 

 him, as it did myself, that the arrangement is very 

 similar to what is observed in the coloured side of 

 the choroid coat of the eye, when covered with its 

 pigment. To preserve, therefore, the beauty of 

 spiders, this must be untouched. In my first at. 

 tempts, not being aware of this, I destroyed almost 

 all of them, as here and there only spots of colour 

 remained, the greater part being transparent. At 

 length I succeeded most perfectly ; and I have now 

 in my possession some spiders put up so long ago 

 as 1S25 and 1S27, as bright with their silvery 

 bands, and others with their blue and red streaks, 

 as the day when they were first preserved. 



In the year 1825 or 1820, Admiral (then Captain) 

 Dupern', in thePrench corvette Coquille, when on a 

 voyage of discovery, put into the Mauritius, I made 

 his acquaintance, and while examining my collection, 



the spiders at once attracted his attention, and he 

 seemed so struck with the specimens I then had, 

 that he requested permission to bring his naturalist 

 to see them, and to give him some information as to 

 the mode of preserving them. He also made me an 

 offer of anything in exchange for the spiders from 

 the numerous collection of objects of interest on 

 board his frigate. I readily consented, and received 

 from him shells (the study of which was then my 

 hobby) such as I had not before possessed. Con- 

 ceive my surprise and pleasure, when visiting the 

 Museum in the Jardin des Plantes,'in Paris, in the 

 year 1851, upwards of a quarter of a century after, 

 to find those I had given him in perfect pre- 

 servation, maintaining all their colours in their 

 original brightness, well distended, and in good 

 shape, and labelled with my name. I mention this 

 to show that the method I adopted is just as 

 permauent as that for the preservation of any other 

 similar object. 



The plan is as follows : Make an incision along 

 the ventral aspect of the abdomen nearly its whole 

 length, or as long as will euable the pulpy contents 

 to be easily removed ; then pinch up the pulpy 

 mass with a small forceps, carefully avoiding any 

 dragging; then with a sharp-pointed scissors cut 

 away the contents bit by bit until the whole is 

 nearly removed, or until you can see the brilliant 

 colour shining through what remains in the cavity 

 — better leave a little too much than be too nice in 

 clearing all away ; — then with a blowpipe distend 

 the empty abdomen : it will very soon become firm, 

 and retain its original form ; but until it is so the 

 blowing must be frequently repeated. How long in 

 our cold climate this may be required I can hardly 

 say ; but in the tropics, where the heat in the sun 

 during the day is seldom under 120°, or even 140°, 

 three or four times a day, for a couple of days, was 

 quite sufficient to keep them permanently distended, 

 as well as perfectly harden any of the contents 

 which it was thought right to leave. 



This was generally all that was required before 

 placing them in their future abode ; but sometimes 

 I have coated the interior with a preservative which 

 I have always employed for the bodies of beetles, 

 moths, and even butterflies — for I empty ; all and the 

 results, that all my cases of insects are as free from 

 dust arising from the decay of animal matter as when 

 originally put up. Sometimes in the larger-bodied 

 Tarantula} or moths I have stuffed them with cotton- 

 wool wetted in the preservative ; but generally 

 this is not necessary. The frequent distention by 

 blowing along with a heated atmosphere will be 

 perfectly suilicient to prevent any future shrivelling. 



I add the preservative, as it may be useful to 

 others : — 



Corrosive sublimate, 5ii. 

 Spirit of wine (a pound), 5xvi. 

 Camphor 5ss. Mixed. 



