318 



EEPORT — 1879. 



then the green lines of magnesium, (b) then hlue line, then various mixtures of all of 

 them, as the temperature is increased, D being always the brightest. 2 volumes 

 (i cc) of hydrogen only were collected. 



4. With gallium and arsenic the pump always clicks, indicating that no gas is 

 given off. 



5. From sulphur and some of its compounds there is always So 3 . 



6. From indium, hydrogen comes over before heating. 



7. Lithium gives 100 volumes of hydrogen. 



The conditions of the experiments have always been the same, the only variable 

 bein 0- the substance. The volumes stated are those generally obtained ; almost all 

 experiments are ended by the cracking of the tube. 



8. Notes on} Petroleum Spirit or 'Benzoline.' 

 By Alfred H. Allen. 



The application of the commercial names "' benzoline ' and ' benzine ' to the 

 more volatile portion of petroleum has led to great confusion between petroleum 

 spirit and coal-tar naphtha, the most characteristic constituent of which is the 

 hydrocarbon benzene or benzol. 



Although presenting close general resemblances, the following characteristic 

 differences exist between petroleum spirit and coal-tar naphtha. All the tests 

 given have been carefully verified by the author on representative samples of 

 petroleum spirit and coal-tar benzol. 



Petroleum Spirit, ' Benzoline ' or ' Benzine.' 



1. Consists of heptane, C 7 H 16 , and its 



homologues. 



2. Heptane contains 84-0 per cent, of 



carbon. 



3. Commences to boil at 54° to 60° C. 



4. Specific gravity at 155° C. about 



•69 to -72. 



5. Smells of petroleum. 



8. Dissolves iodine, forming a solution 

 of a raspberry-red colour. 



7. Does not sensibly dissolve coal-tar 



pitch, and is scarcely coloured by 

 it, even on prolonged contact. 



8. When shaken in the cold with one- 



third of its volume of fused 

 crystals of absolute carbolic acid, 

 the latter remains undissolved, 

 and forms a separate lower 

 stratum. 



9. Requires two volumes of absolute 



alcohol, or four or five volumes 

 of methylated spirit of -828 sp. 

 gravity, for complete solution at 

 the ordinary temperature. 

 10. Warmed with four measures of 

 nitric acid of 1-45 sp. gravity 

 the acid is coloured brown, but 

 the spirit is little acted on, and 

 forms an upper layer. 



Coal-Tar Naphtha, or 'Benzol? 



1. Consists of benzene, C C H 6 , and its 



homologues. 



2. Benzene contains 92 - 3 per cent, of 



carbon. 



3. Commences to boil at about 80° C. 



4. Specific gravity about - 88. 



5. Smells of coal-tar. 



6. Dissolves iodine, formiug a purple- 



red liquid of the tint of an 

 aqueous solution of potassium 

 permanganate. 



7. Readily dissolves coal-tar pitch, 



forming a deep-brown solution. 



8. Miscible with absolute carbolic acid 



in all proportions. 



9. Miscible with absolute alcohol in 

 all proportions. Forms a homo- 

 geneous liquid with an equal 

 measure of methylated spirit of 

 •828 sp. gravity. 

 10. Completely miscible with four mea- 

 sures of nitric acid of 1*45 sp. 

 gravity, with great rise of tem- 

 perature and production of dark 

 brown colour. (A certain amount 

 of nitrobenzene may rise on 

 cooling the liquid.) 



