INSECT VAiaETY. 4^) 



Lathohxam [f), common on pathways during early sunshine ol' 

 the year, it tlavours stron<^ly of ratafia ; while in Staphylinus we 

 detect, again, the savour of musk, or in the large " Cocktails " 

 [Goerius) we have a drenching black bottle of viiiahjre. 



Herr Erne, in an interesting memoir on the habits of Velleius 

 dilatatus, a largish short-elytra''d beetle, parasitic in Switzer- 

 land in hornets^ nests, where it sucks the honey and destroys 

 intruding vermin, notices a sharp musky odour of such intensity 

 that five or six of these forbidding earwig-like prowlers will 

 sensibly perfume a room. 



In aquatic beetles, and the tribe of the Heteromera, whose 

 posterior feet or tarsi have only four apparent joints, the 

 secretory ducts are similar in position, and the odour is nauseous, 

 as in the surface Whirligigs {G^riuics), and in the black and 

 lucifugal larder beetles, Blaps ; or the glands are situated at the 

 cephalothoraeic joint, as in the water Dytiscus ; and their etHuvia 

 resembles sulphuretted hydrogen. 



Passing to the light and airy bees, we find certain kinds 

 on touch diffuse pungent scents. Though it must have 

 doubtless been observed by the ancients that when an ant- 

 bed was raked vip with a stick a strong acid smell arose 

 from its atmosphere, the existence of formic acid would 

 appear to have been noticed first by Dr. Hulse in his cor- 

 respondence with Mr. Ray, the doctor informing him that 

 certain ants, if irritated, give out a clear liquid that tinges blue 

 flowers red. This acid has been subsequently obtained in 

 quantity sufBcient for analysis by bruising ants and macerating 

 them in alcohol, and then distilling over, when an acid liquor 

 remains which, saturated with lime, mixed with sulphuric acid, 

 and itself distilled, yields a liquid possessing all the properties of 

 acetic acid. Another more simple method consists in bruising the 

 insects and distilling, or merely infusing, them in water. In either 

 case the resulting acid is said to possess the following properties : 

 — It reddens blue flowers, flies off in the form of a vapour smelling 

 like musk, is decomposed by a great heat, and forms salts with 

 alkalies and earths called formiats, which are crystallizable and 

 not deliquescent. It resembles acetic and malic acids, but is 

 nevertheless distinct in character according to the investigations 

 of Margraaf, Thouvenel, Lister, Arvidson, and Oehn. 



