534 Scientific Intelligence. [Sept. 



posed by ammoniacal gas ; but most other re-agents, provided 

 they be perfectly dry, do not act upon it. The combination of 

 perphosphuretted hydrogen is formed in the same manner with 

 the protophosphuretted ; it possesses nearly the same proper- 

 ties, except that when it is decomposed by water, it is converted 

 into protophosphuretted hydrogen, with the deposition of phos- 

 phorus and hydriodic acid, and that when it is acted upon by 

 ammoniacal gas, it disengages half the volume of the ammo- 

 niacal gas, with a deposition of phosphorus. 



M. Houton Labillardiere draws the following conclusions from 

 his experiments. 1 . That protophosphuretted hydrogen is inflam- 

 mable at ordinary temperatures in atmospheric air, or in oxygen 

 sufficiently rarefied ; 2. That each of the phosphuretted hydro- 

 gens combine with the hydriodic acid ; 3. That these compounds 

 possess different properties ; 4. That the compound formed with 

 protophosphuretted hydrogen gas consists of equal volumes of 

 the two ingredients ; but that the compound formed with per- 

 phosphuretted hydrogen gas consists of one volume of this gas 

 to two of the hydriodic acid gas ; 5. That the phosphuretted 

 hydrogens contain the same volume of hydrogen, and that per- 

 phosphm-etted hydrogen does not change in bulk when it is 

 converted into protophosphuretted hydrogen ; 6. That from the 

 analogy which exists between azote and phosphorus, we may 

 compare their compounds to ammoniacal salts, and may desig- 

 nate these combinations, the hydriodates of the phosphuretted 

 hydrogens. 



X. On Mr. Trittoris Distilling Apparatus. 



(To the Editors of the Annals of Philosophy.) 

 GENTLEMEN, 63, Whitechapel, Aug. 14, 1818. 



I beg to acquaint you that since writing the account of my 

 improved apparatus for distilling, inserted in your number for 

 June last, I have erected one of 400 gallons for trial at this 

 place. It has been worked both with water and spirits, and the 

 result has been most satisfactory, from the regularity and expe- 

 dition with which the still works, the small consumption of fuel, 

 and the improved quality of spirit. A correspondent in the 

 number of the Annals for July, quoting an opinion entertained 

 by Dr. Black and Mr. Watt, that there would be no saving of 

 fuel by distilling in vacuo, I trouble you with this letter to state 

 that the experiments made both on the small scale and with the 

 apparatus just referred to are entirely opposed to such an opinion; 

 and that Mr. Benwell, who has been for 30 years engaged in 

 the malt distillery, and Mr. John Bockett, Jun. an eminent 

 rectifier, permit me to express their entire confidence, from 

 observation on the working of the still, that a material saving of 

 fuel is effected by the use of my improved apparatus. I take 

 this opportunity of stating that I have many times distilled malt 



