1 58 Scientific Intelligence, Sfc. 



may be propagated by a repulsive force, the intensity of which varies 

 inversely as the square of the distance. These conclusions depend 

 upon two facts. 1. That diaphanous bodies exist in nature. 2. That 

 the particles of ether during luminous vibrations oscillate on the 

 surface of the undulations. 



He has further deduced, from experiments and calculations, that 

 under the influence of a single species of light, the ether which sur- 

 rounds ponderable particles may be divided into an infinite number 

 of different systems whose motions are isochronal. 



XVIII. — Globules of the Zannichellia palustris. 



M. Pouchet has observed in the juice of the common horned pond 

 weed, aplant very frequentin Britain, two kinds of moveable vesicles, 

 the one opaque and bristly, the other transparent and smooth. They 

 possess a similar structure with the vesicles of the pollen. In the inte- 

 rior of the smooth vesicles, he observed smaller secondary vesicles and 

 very fine corpuscles. These corpuscles analogousto those which exist in 

 the grains of the pollen are most frequently moveable ; they are sepe- 

 rated from each other, but sometimes united in one irregular globular 

 mass they move altogether. 



XIX. — White Crystalline Grains in the Intestines. 



The body of a woman, who was supposed to have been poisoned, 

 was exhumated. The excrementitial matter was well washed with 

 repeated additions of water. M. Braconnot observed in the residue 

 a white sandy substance, which disengaged a fetid odour when 

 thrown on charcoal. It consisted of grains, each of which was a 

 tetrahedral prism, terminated by a pyramid with two, three, or four 

 faces. The colourless crystals when exposed to the air lost their 

 transparency. They were not sensibly soluble in water. Warm 

 dilute nitric acid dissolved them readily, with a slight effervescence. 

 Ammonia poured into the solution formed a white precipitate, which 

 disappeared on the addition of dilute sulphuric acid. When exposed 

 to heat on platinum foil they lost their transparency, and fused into 

 a grayish residue. Before the blowpipe they fused into a white 

 enamel. With potash they give out an ammoniacal smell, and leave 

 magnesia ; heated in a glass tube with a little muriatic acid, they 

 afford a sublimate of sal ammoniac. Before the blowpipe with 

 nitrate of cobalt a reddish glass is produced, and with boracic acid 

 and iron phosphuret of iron is formed. Hence they appear to be the 

 ammoniaco magnesian phosphate. 



Denis, Henri, and Guibourt found some crystals in the intestines 

 likewise, in a case which they at first mistook for arsenic, but they 

 did not determine their composition. 



Braconnot once observed similar crystals in a case of poisoning by 

 arsenic. Warm dilute nitric acid dissolved them, but the abundant 

 flocky precipitate formed with solution by ammonia was insoluble in 

 sulphuric acid, which converted it into sulphate of lime. They 



