JtLv, 1901.] 



KNOWLEDGE. 



163 



Several points in the struct me of Aopus deserve a 

 l^issing mention. Wings seem to bo quite- .ibsciit. The 

 widened fore-shin, as in several other ground-beetles (in- 



%M^ 



Fio. 12. Fio. 13. 



Fio. 12. — Gmb of Aepi'.s marittus. (Afler Wc^twood.) Miit^nilioil 

 20 times. 



Flo. I'-i. — Aeptis Bohinii. JIaguilied 20 times. L, second umxillie 

 (labium), luagiiified 40 times, {p, palp.) 



eluding Cillenus), has a deep bristle-fringed notch to- 

 wards its far end ; this serves as a comb for cleaning the 

 feelers, which can be drawn through the notch so that 

 particles of saiid are removed by the bristles. The com- 

 pound eye of Aepus is composed of a relatively small 

 number of circular facets ; the eye in marine insects is 

 frequently thus, instead of being built up of an immense 

 number of hexagonal facets. Behind the facets, accord- 

 ing to Prof. Miall, is situated a concave plate with a 

 circular opening; "the form of this plate,' he writes, 

 ■' suggests that it may be employed as a kind of pin-hole 

 camera. " Another interesting fact discovered by Prof. 

 Miall and Mr. Hammond, is the presence of a pair of 

 large air-sacs at the binder end of the abdomen in 

 Aepus; these "are no doubt useful during prolonged 

 submersion.' These beetles are provided with long 

 bristly hairs, which, as Audouin** noticed nearly seventy 

 years ago, serve to entangle air-bubbles when the insect 

 is submerged. " If," he wrote, " one transfers the insect 

 directly from the air into sea-water, one notices that each 

 of its hairs holds a little layer of the surface film, 

 which forming at first tiny spheroids soon unite into a 

 little globule which surrounds its body on every side, 

 and which, despite the agitation resulting from 

 the insect running under the water .... never 

 escapes. Our insect always can'ies about a little 

 layer of air, and when it hides beneath a stone, it finds 

 itself at once in the condition of insects living freely in 

 the atmosphere." Coquerelft made some experiments as 

 to the length of time which Aepus can remain under 

 water. Their habit when the tide rises is to take 

 shelter beneath stones and remain there till the ebb 

 again sets them free. Coquerel found that when im- 

 mersed under artificial conditions for a very long time 

 ■' they always finally fell into a state of apparent death. 



•• J. V. Aurlouin. ■■ Observations but un lasccte C'oleoptere i|ui 

 passe line prandc partie de sa vie sous la Mer. " Kouv. Ann. Miis. 

 Hint. Nat., III., 1833, pp. 117 127. 



t+ C. Coquerel. " Xote pour servir ii I'lri.stoire de lAepus Kobinii 

 et description de sa Larve." Ann. Hoc. Ent. France (2), VIII., 1850, 

 pp. 529-532. 



I have kept them thus," ho writes, "for eighteen hour? 

 under water. I believed them dead, but having placed 

 them in the sun on a sheet of paper, Ihcv revived after 

 some minutes and began to run about as before." 



Like its parent beetle the gnib of Aepus has a very 

 large head, armed with sharp, strong mandibles, and is 

 very active in its habits when the tide is out. The hairy 

 covering wherewith it is provided hclp.s to entangle air- 

 bubbles. Both beetles and grubs are believed to prey on 

 small molluscs, such as Rissoa, in whose company they 

 are often found. 



There is something fascinating in the study of the life 

 of these small beetles, spending, as they must, the greater 

 part of their time under stones on the sea bottom, wait- 

 ing for the fall of tho tide to allow them a few hours' 

 activity in tho air, which is, after all, their true element. 

 The observer on the shore, as he watches tho breakcirs 

 rolling in at tho flood, may well give a thought to tho 

 tiny insects, safe in their hiding-places far beneath the 

 restless waves, waiting there patiently until the ebb shall 

 rcloasc them once again from their watery prison. 



STANDARD SILVER: ITS HISTORY, 

 PROPERTIES AND USES. 11 1. 



By Ernest A. Smith, assoc. r.s.m., f.c.s. 



It is well known that silver wares, when exposed to 

 ordinary atniospheric influences, soon become disfigured 

 by blotches of tarnish, due to the action of the sulphur 

 in the air, and in consequence require to be repeatedly 

 cleaned to present a bright appearance. 



This being one of the drawbacks to silver goods a 

 few remarks on this subject are not without interest, as 

 the sui'face will become perfectly black in a few months 

 time if continual cleaning is neglected. 



Some interesting directions for the care and cleaning 

 of silver-gilt plate are preserved with the chiuch-plate 

 of Stinsford, in Dorsetshire.* The directions, which arc 

 dated June, 1737, are given by Paul Lamerie, the 

 silversmith who made the plate. They run as follows : — 

 " Clean it now and then with only warm water and soap, 

 with a Spunge, and then wash it with clean water, and 

 dry it very well with a soft Liiuien Cloth, and keep it 

 in a di-y place, for the damp will spoyle it." 



The instructions given by tho silversmith who made 

 the plate for Carlisle Cathedral in 1679 may be com- 

 pared with the above extract as they are equally worth 

 attention. " Be carefuU," he says, " to wipe it with a 

 clean soft linnen cloath, and if there chance bo any 

 Staines or spotts that will not easily come off with a 

 little water, the cloath being dipp'd therein, and so 

 rubb the flagons and chalices from the topp to the 

 Bottome, not cross wise, but tho Bason and patens are 

 to be i-ubb'd roundwise, not acrosse, and by }ioe means 

 use either chalkc, sand, or salt." These last words 

 cannot be too strongly emphasised, as much damage 

 is frequently done to silver plate by excessive rubbing 

 and the use of injurious cleaning materials. The 

 simple directions given by Paul Lamerie and his brother 

 silversmith still serve as a good guide for cleaning plate. 

 By the adoption of the following process it is statedt 

 that largo stocks of silver articles may be protected 

 against atmospheric influences and will remain as bright 

 as when first new. 



» Quoted by Cripps, " Old Englisli Plate," 0th Kdit., 1899, p. lO. 

 t "Jeweller and Metalworker," \'ol. XX\'I. (1900), p. 102. 



