HARDWICKE'S SCIENCE-GOSSIP. 



255 



of this beetle in some seasons cause much injury by 

 eating off the leaves of the asparagus and gnawing 

 the tender shoots. 



Remedies. — Syringe the infected shoots with a 

 mixture of soft soap, powdered sulphur, and warm 

 water. 



Burying beetle (Niecrophilus vespilld). This insect 

 is very useful in burying dead animals (such as small 

 birds, moles, and mice) beneath the soil, thus 

 preventing disagreeable smells in hot weather, and 

 excluding the possibility of the dissemination of 

 malaria. 



Besides exhibiting the imago of each insect, it is 

 very desirable that the larva pupa and ova should 

 also be shown, or if specimens of any of them 

 cannot be obtained a drawing may be substituted. 

 Specimens of the various food crops with samples of 

 the injury done would add greatly to the value of the 

 collection. 



Such a collection as the one we have here suggested 

 would be found both interesting and instructive, and 

 we can recommend the formation of one to anybody 

 as a very pleasant occupation. To every person who 

 desires to promote the welfare and prosperity of 

 himself and fellow-men here is an opportunity not to 

 be neglected. 



Any further information I shall be very pleased to 

 supply to the best of my ability. 



Ladyivood, Birmingham. 



GOSSIP ON CURRENT TOFICS. 

 By W. Mattieu Williams, F.R.A.S., F.C.S. 



PECULIAR GYMNASTICS.— Mr. Edward 

 Horace Man has written an interesting volume 

 " On the Aboriginal Inhabitants of the Andaman 

 Islands," in which he describes, among other customs, 

 a habit common among the young men and women 

 of twisting their bodies from side to side, to stretch 

 the muscles of the back after lengthened rest or 

 sedentary occupation. In doing this they produce a 

 succession of sounds like those caused by the cracking 

 of the joints of one's fingers. 



This practice is by no means confined to the 

 Andaman Islanders. Among my fellow-students in 

 Edinburgh was a young Turk, by no means a 

 savage, but a highly-educated gentleman, bearing, of 

 course, the title of Effendi. He was working hard 

 for the medical degree, and after a long spell of 

 reading, he refreshed his brain by going through a 

 curious drill or series of exercises. These consisted of 

 sitting cross-legged on the floor, rising and sitting 

 again several times without help from the hands ; 

 then making a series of movements of the arms, 

 then cracking all the joints of his fingers, elbow, and 

 shoulder, and finally proceeding with similar cracking 

 of the vertebrae and some of the lower joints. He 



told me that such gymnastics constituted a customary 

 part of the training of youths who received a liberal 

 education in Turkey. 



Shortly after witnessing this performance I was 

 cruelly snubbed by an anatomist to whom I described 

 it. He demonstrated the impossibility of thus 

 cracking the vertebra?, basing his demonstration on 

 the elasticity of the cartilages which would prevent 

 any momentary separation, and further on the 

 damage which such displacement must do to the 

 spinal cord. He was too eminent, and too well 

 satisfied with his own eminence, to regard my state- 

 ment of fact witnessed by myself. I was as com- 

 pletely crushed as any of the numerous mariners who 

 have seen a sea serpent and have been sufficiently 

 rash to describe it. Therefore I now find much 

 consolation in Mr. Man's account of the peculiar 

 gymnastics of the Andaman islanders. 



New ExrLOSivES. — An explosive substance is a 

 solid or liquid which by some means — such as per- 

 cussion, or other mechanical agitation, or the appli- 

 cation of heat — becomes suddenly converted into a 

 gas or mixture of gases ; the sudden expansion 

 producing detonation and mechanical violence. 

 Chloride of nitrogen is a simple example. It is a 

 liquid composed of two elements, both of which are 

 gaseous under ordinary conditions, and in the liquid 

 compound are held together by such very weak 

 affinity that they are severed by the slightest shock. 

 The touch of a feather is sufficient to dissociate the 

 liquid into its component gases with fearful explosion. 



Gunpowder is a mixture of two solids (carbon and 

 sulphur), the oxides of which are gaseous. To these 

 are added saltpetre, a substance which when heated 

 to about 6oo° Fahr., gives off active nascent oxygen, 

 which by combining with the carbon and sulphur 

 produce both of the gaseous oxides. Gun cotton is 

 another example, where the fibre is nitrated or 

 supplied with a compound readily giving up its oxygen 

 to the carbon ; nitro-glycerine and its modification 

 known as dynamite are other examples. White gun- 

 powder and many of the compounds of the pyrotechnist 

 are similar, with chloric acid instead of nitric as 

 the source of oxygen. 



Permanganic acid and the permanganates give up 

 their excess of oxygen with remarkable facility. 

 Upon this their use as disinfectants or deodorants 

 chiefly depends. M. Klobb, of Nancy, has recently 

 produced some permanganic ammonia salts of metals, 

 such as silver, copper, nickel, cobalt, &c, that are 

 remarkable for the beauty of their crystals and their 

 explosive properties. They detonate when warmed 

 or rubbed. The explosion in these cases appears to 

 be due to a liberation of oxygen with ammoniacal 

 gas. 



Sources of Ginger. — The friends of temperance 

 (and we are all such friends, whether we talk loudly 



