70 Scientific Intelligence. 



and resorted to by pilgrims in great numbers. Bubbles of gas rise up 

 through it, which Dr. Daubeny found to consist of 



Nitrogen 94. Oxygen 6. 

 The spring gushes out of the same limestone stratum, asjthat of 

 Mallow. 



IFovejnber 20th. A notice was communicated from Mr. Kirtland 

 respecting the worm exhibited at the last meeting by Mr. Kynaston, 

 which had apparently destroyed a grasshopper. It is found to be the 

 gordius aquaticits, or hair worm, so called from various contortions 

 and knots into which it twists itself. In a communication made to 

 Loudon's Magazine, vol. ii. p. 211, it is said to be often met with on 

 the surface of garden or other ground in wet weather, as it is in 

 water or clay, its common habitation. 



The gordius aquations is not unfrequently found to inhabit the 

 intestines of insects. De Geer (marshall of the court of the queen 

 of Sweden, and member of the Academy of Stockholm, and who 

 published a work intitled " Memoires pour servir a l'Histoire des 

 Insectes" in 7 vol. 4to. 1752 — 1779) mentions these worms being 

 found in grasshoppers. Dr. Matthey likewise mentions one of 

 these worms being found in the body of a grasshopper, which was 

 no less than2-\ feet in length. 



Mr. Paxton mentioned a similar case in the instance of an earwig. 



Mr. Johnson of Queen's, read a short account of some mathe- 

 matical researches he had lately pursued on optical images. He was 

 led to this remarkable result, that, according to the mathematical 

 theory, the image of a straight line placed vertically in water, and 

 also horizontally, are each the loci of equations of high dimensions 

 and great complexity, and should be curves of high orders, but to the 

 eye they are straight lines ; a very accurate construction of the curves, 

 however, shewed that certain portions of them (which properly repre- 

 sent the image) will approach so near to straight lines as to be such 

 to the eye. Drawings of these curves were exhibited. 



Mr. Powell gave a communication on the dispersion of light, in 

 continuation of former papers, in which he illustrated the subject by 

 diagrams of the several spectra formed by prisms of water, oil of 

 turpentine, flint glass, oil of cassia, oil of aniseed, and sulphuret of 

 carbon, shewing their comparative refractive and dispersive powers. 



Dr. Buckland read a further statement relative to the luminous 

 appearance on the flowers of the Oenothera, mentioned at the last 

 meeting. It was distinctly stated that the luminous appearance con- 

 tinued uninteruptedly for a considerable length of time : it did not 

 appear to resemble any electric effect : and the opinion which seemed 

 most probable was, tha„ the plant, like many known instances, has a 

 power of absorbing light, and giving it out under peculiar circum- 

 stances. 



Dr. Daubeny exhibited some specimens of sand and clay found in 

 the bottom of the caverns, in limestone, at Michell's town, near Cork. 

 The sand covered the bottom of the cave to an unknown depth, and 

 was itself covered with a crust of stalagmite. The sand must have 

 been washed in through a very narrow entrance ; and there is no 



