♦ KNOWLEDGE ♦ 



[Aug. 21, 1885. 



featluT clutliing is misunderstuod to a greater extent 

 tlian I anticipated. Thus " G. A.," in Kxowledge, 

 Aug. 7, p. 122, still contends that the oil-glands of the 

 duck are used for oiling the feathers by a painting action 

 of the beak, head, and throat. As already stated, I do 

 not question the structure of the uropigium, as described 

 b}-"G. A.," and have no objection to calling it an oil- 

 gland. I n-.r,l it simply as an exaggerated pair of 



the tails of cocks and liens, which, as Ray says, p.ve pul- 

 vcratrices. They powder their feathers with dust, which 

 would become dirty adhesive paint if the secretion of 

 the heart-shaped glands were used for oiling them. 

 Besides this, I have examined the bill, head, neck, and 

 back of a duck after it has nibbled and i-iiLlied in the 

 manner described by " G. A.," and {• ■' ' \ ' Hiat 



these parts are then or at any other i ■ :)i 



any such fat or oil as stated, the su: j '.s 



aj-e demonstrably less greasy than huii;:i ! lit- 



seen by rubbing a cle.in piece of metal or glass up' n' the 

 feathers of the head and neck of the duck^and a similar 

 piece in like manner on one's own face and neck, and then 

 comparing the smear. The ducks and swans in our London 

 parks supply further proof. The white species remain 

 white, instead of sharing the colour of London sheep, which 

 they undoubtedly would if their feathers were greasy or 

 oily like the wool, and exposed to the carbon flocculi 

 which shower through our London atmosphere. The 

 brushing action of the head and neck is not always pre- 

 ceded by a pinching of the oil-glands, nor usually so, as 

 anybody may leam by watching the ducks in our parks. 

 They clean their feathers, but do not smear them. 



Upon i'}:.i question of whether the water repulsion de- 

 pends upon oiling of feathers or upon the adhesion of a 

 film of air to them depends the verdict we must pass 

 upon the desirability of using feathei-s for bedding and 

 for clothing. At one time I joined with high sanitary 

 authorities in denouncing feather-beds on the ground 

 that, being organic animal matter, they should be liable 

 to organic decomposition, and to saturation with con- 

 densed cataneons exhalations. It is not very long ago 

 since I wrote to my friend Dr. Richardson on the subject ; 

 but further investigation now induces me to recant, and 

 the grounds of this recantation are the same as my re- 

 pudiation of the supposed feather-oiling by ducks. 



I find that feather fibres generally (I say "fibres" in order 

 to exclude feather quills) are remarkably free from greasi- 

 ness or humidity, more so than any other animal structure 

 that I am acquainted with. I find also that they are 

 exceptionally free from the vice of condensing sebaceous 

 and other skin exhalations on their surface ; that while 

 cotton, linen, woollen, and silken fabrics become defiled 

 by perspiration, feathers, similarly exposed, remain clean. 

 The contents of a flock-bed after a few years of con- 

 tinuous u^e become matted and foul, while those of a 

 goose-down bed after a similar or much longer \ eriod 

 remain untainted ; tie y . i :.'.v .\i:-: •:. ;',' ! ■ , - ;, f!v 

 due to the fracture of f : ■: " i ,. ", |i ,, i/d 



feathers from a bed t ! : ] ' , 1 1- 



tinuous use, and fii.J iii;*, ;.l'tr :, >'i;^li' -i','.,:, the 

 feathers are as clean as when they were new. Xot so 

 the enveloping fabric either inside or out, although it has 

 been washed and renewed frequently during the lifetime 

 of the feathers. 



This, if am not altogether mistaken, depends upon the 



fact that every filament of the down attaches to itself an 

 obstinately-adherent film of air, which prevents the con- 

 densation of moisture on its solid surface. Thus we may 

 lie on a feather-bed in a hollow formed by the pressure 

 of our bodies, may perspire freely and moisten the 

 coverings of the feathers, and yet the feathers themselves 

 shall remain dry and untainted, the vapour diffusing 

 itself throughout their adherent atmospheres. The 

 advantage of this is obvious. 



Down skirts are made and used, and must be far better 

 than ordinary skirts of similar form, as the required 

 amount of protection is obtained with far less weight. 

 "\^Tienever the merciless despotism of fashion may 

 command its slavish victims to render themselves 

 hideous by exaggerated nether expansions, either behind, 

 or in front, or all round, the unfortunate creatures will 

 suffer less by using light eidei'-down enlargements rather 

 than metal cages or other heavy substrata. Let me not 

 be misunderstood ; I am not recommending such things 

 on their own merits, but only as lesser evils in the 

 meantime, until we can afford to erect lunatic asylums 

 of suiBcient capacity to stamp out the fundamental evil. 



Feathers have been used as clothing materials by the 

 most primitive of savages, usually by attaching the quill 

 ends of the feathers to each other, and thus building up 

 a mosaic fabric of highly ornamental as well as useful 

 character. That from the South Sea Islands, exhibited 



by L:iil\- ]'.] ■. : ' Sriuth Kensington last year, is a fine 



exam] S . ; ' ! " i 1 le of great value. The labour ex- 

 pendi.l (II I , i 1 \ .-((uare yard of such material must be 

 immense ; but " wliether it may be siibstituted by 

 machinery I am unable to say. Another and a better 

 mode of availing oureelves of the valuable clothing pro- 

 perties of feathers suggests itself, viz., that of carding- 

 and weaving the filaments of down, such as common 

 duck and goose down, swans-down, &c. This appears to 

 me to be quite a soluble problem, and I recommend it 

 accordingly to the attention of ingenious mechanicians, 

 believing firmlj- that such a fabric would, for ordiaary 

 clothing purposes, excel all others in liL'htness, warmth, 

 and durability, with the additional excellence of allowing 

 free passage of the perspiration and being waterproof 

 without any oiling. 



Vests and shirts of woven down would, I hare no 

 doubt, attain the nearest possible approach to perfection 

 in underclothing for both winter and summer. They 

 may, probably, be difficult to clean. Ordinary scrubbing 

 with soap and water and soda is not likely to succeed. 

 The laundress of the future in dealing with these will 

 have to take lessons from the birds, pirobably from the 

 2>ulueratrices above-named, and use cleansing powders 

 applied with the aid of suitable brushes — feather brushes, 

 like the duck's head. 



OUR HOUSEHOLD INSECTS. 



By E. a. Butleb. 



COLEOPTEEA (continued). 



OS'E of the finest, though at the same time most 

 destructive, divisions of the beetle order is that 

 called Lonsicornia, or Longhorns. The beetles arc many 

 of them remarkably handsome and of coiisi leraMe size, 

 and are readily distinguished by the gri • ' ■ ' '' • 1 , fi- 

 antenna?, which, in some cases, many t ; < u 



that of the body itself. These inseei -, . . . : vul 



condition, burrow into the solid wood oi" timltr irees, 

 where they live, often from three to five years, devouring 



