102 
POPULAR SCIENCE REVIEW. 
Synthesis of Hydrocarbons. — Friedel and Crafts have recently published a 
valuable series of papers on a new method, of general application, for the 
synthesis of hydrocarbons, acetones, &c. (“ Journ. Prakt. Chem.,” 1877, xvi. 
p. 233.) The chemical changes are brought about by the action of aluminium 
chloride. When to aruylic chloride dissolved io benzol some of the metallic 
chloride is added, hydrochloric acid is set free, and amyl-benzol is formed : — 
C 5 H n Cl + C 6 H 6 = II Cl + C 6 H 5 (C 5 H n ). 
If an organic bromide or iodide be taken in place of a chloride, a similar 
reaction is noticed : ethjlic iodide, for example, in the presence of benzol and 
the metallic chloride forms hydriodic acid and ethyl-benzol : 
0 2 H 5 1 + C 6 H 6 = H I + C 6 H 5 (C a H 5 ). 
Methylic chloride dissolved in benzol under similar conditions produces 
toluol ; and when two, three, or four molecules of methylic chloride 
react on one molecule of benzol in presence of aluminium chloride, xylol, 
mesitylen and durol are produced, a corresponding number of molecules of 
hydrochloric acid being set free. Under similar circumstances benzylic 
chloride yields diphenylmethane. Bodies containing more than one atom of 
chlorine are also acted upon in a like sense when in contact with benzol and 
the metallic chloride; chloroform produces triphenylm ethane, and carbon 
tetrachloride tetraphenylmethane. Benzoic and acetic chloride form respec- 
tively benzophenon and acetophenon. Other metallic chlorides resemble 
that of aluminium in their ability to withdraw hydrochloric acid; iron 
perchloride acts at ordinary temperatures, and iron protochloride when heat 
is applied. The authors are of opinion that in the first stage of the reaction, 
which we have considered, an organic compound containing aluminium is 
formed, which then undergoes decomposition, setting the aluminium chloride 
once more free. The case where benzylic chloride enters into the reaction, 
for example, would be represented thus : — 
C 6 H 6 + Al 2 01, = H Cl + 01 5 , C 6 H 5 
' Y ' 
hypothetical compound. 
Ale 01 6 (0, H s ) + (C H s C 6 H s ) Cl = Al 2 Ole + (0 H 2 C 6 H s ) C 6 H 5 
Diphenylmethane. 
Phosphorescence of the Salts of Quinine. — It has been noticed by Landerer 
(“ Ard. Pharm.,” [3] x. p. 322) that quinine sulphate becomes phosphorescent 
at 40° to 50° R. If some of the salt, strewn over a sheet of smooth paper, be 
placed on a plate of metal and exposed to this temperature, it becomes 
beautifully phosphorescent when stirred with a glass rod, the light being 
observed for some minutes. Valerate of quinine exhibits the same phe- 
nomenon, even when heat is not applied ; if a few crystals be rubbed or 
struck in a mortar a luminous appearance is observed with each blow of the 
pestle. The phenomenon, it seems, is only noticed when use is made of 
valerate containing acid which has been prepared directly from the root of 
the valerian. 
Pdyporic Acid. — This acid has been obtained by Stahlschmidt from 
several species of Polyporus (“ Annalen der Chemie,” 1877, clxxxvii. p. 177). 
