1821.] Scientific Intelligence. 155 



accompanying minerals, and I may add that the specimens in question 

 were broken from a fresh rock in which they were deeply imbedded* 

 The preceding characters seem to distinguish it for the present from 

 all the mineral substances hitherto described ; and the term conite 

 appears well adapted for it, as being expressive of its most conspicuous 

 feature. 



*' On this substance I shall only remark as I recently did on treating- 

 of Rum, that it is preferable to erect a species, though it should after- 

 wards prove a variety of some known substance, than to neglect the 

 obscure characters which minerals often present. It is to greater 

 accuracy of research and of knowledge that we are indebted to the 

 recent rapid augmentation of the list of minerals." (Vol. i. p. 578.) 



III. Production of Artificial Cold. 



When on Ben More in Mull, about 3097 feet high, Dr. Maccullocli 

 made the following observation. — " On this mountain I was accident- 

 ally led to observe the degree of cold produced by the mixture of ice 

 and alcohol. A storm of hail had fallen, accompanied by a tempera- 

 ture below freezing. Some whiskey, the usual appendage of a High- 

 land vieticum, being produced, I was obliged to dilute it by putting 

 some hail into the cup. In an instant the metal was covered with ice, 

 and frozen to the glass: on trial, the quicksilver in the thermometer 

 sunk into the bulb. On repeating the experiment afterwards with 

 common alcohol, the cold was found to amount to 49° or 50°. It 

 presents a convenient method of obtaining a low temperature, wlieix 

 other less common materials are not at hand." (Western Islands, vol. u 

 p. 52^,) . 



IV. Mercurial Atmosphere. 



It has been long admitted that in the upper part of the thermometer 

 and barometer an atmosphere of mercury exists, having a very small 

 degree of tension; and Mr. Faraday has shown, by the following 

 simple experiment, that a mercurial atmosphere may exist without 

 removing the air. A small portion of mercury was put through a fun- 

 nel into a clean dry bottle, capable of holding about six ounces, and 

 formed a stratum at the bottom, not one-eighth of an inch in thickness ;. 

 particular care was taken that none of the mercury should adhere to 

 the upper part of the inside of the bottle. A small piece of leaf-gold 

 was then attached to the under part of the stopper of the bottle ; so 

 that when the stopper was put into its place, the leaf-gold was inclosed 

 in the bottle. It was then set aside in a safe place, which happened to 

 be both dark and cool, and left for between six weeks and two 

 months. At the end of that time, it was examined, and the leaf-gold 

 was found whitened by a quantity of mercury, through every part of the 

 Jjottle, and mercury remained apparently just as before. 



This experiment was repeated several times, showing that mercury is 

 always surrounded by an atmosphere of the same substance. — (Faraday, 

 Quarterly Journal of Science, No.xx. p. 355.) 



V. Sulphur et oj" Chrome. 

 Mr. I, L. Lassaigne has obtained this compound by the following 

 process : Chloride of chrome was prepared by boiling chromic acid with 

 excess of muriatic and evaporating to dryness. It was then mixed 



