516 



ILLUMINATION". 



graduated to cubic centimetres, are introduced 

 beneath tbe condenser, these being on a mov- 

 able support, so as to be slid in succession un- 

 der it, in order to catch the oils carried over at 

 different temperatures. The temperatures are 

 shown by a thermometer (Centigrade) which 

 has its bulb inserted through a tubulure, with- 

 in the retort, but above the surface of the oil 

 introduced. 



In using this instrument, 100 cubic centime- 

 tres of the oil to be tested are introduced by 

 means of a pipette through the tubulure into 

 the retort; the thermometer is adjusted, and 

 heat applied. Let it now be supposed that 

 the first of the five graduated glass vessels is 

 placed so as to receive the oil recondensed from 

 the vapors which distil over from the time of 

 the first application of heat until the thermom- 

 eter (0.) shows 100=212F.; this portion 

 will, of course, contain the lightest of the com- 

 ponents of the oil tested. At the moment the 

 mercury passes 100 the second glass vessel is 

 slid under the tube of the condenser, and kept 

 there (say) until the thermometer marks 120 = 

 248F. In this manner the five vessels may be 

 made to receive successively the oils which dis- 

 til over, first below 100, and then within 

 every 20 of increased temperature, from 100 

 up to 180=356F. It is evident that any 

 other desired even ranges of temperature may 

 be taken; making the first change, say, at 

 44C.=113F., or thereabouts, so as to separate 

 and determine, first, the proportion of oils 

 present which are so volatile as to be unsafe 

 components of an oil for ordinary illuminating 

 purposes. Now, in any case, if the flow of cold 

 water be uniformly kept up through the con- 

 densing apparatus, and if it be sufficient, all 

 the vapors distilled over will be condensed, and 

 the several portions of oil being furthermore, 

 as caught, of equal or nearly equal tempera- 

 tures, a comparison can directly be made be- 

 tween them; and*just 100 cubic centimetres 

 of oil, having been introduced into the retort, 

 the quantities in the several graduated vessels 

 supposing them to have the same tempera- 

 tures as the oil when originally introduced 

 will show the exact percentage of oils, having 

 their vaporizing points between the degrees 

 successively taken, which were contained in 

 the mixed oil at the first. 



Even this method does not, it will be seen, 

 give a strict chemical analysis of the oils test- 

 ed, but only a proximate analysis, by means of 

 the comparative volatility of the component 

 oils. In a discussion upon this instrument, be- 

 fore the Polytechnic Association of New York 

 (Feb. 25th, 1864), the question having been 

 raised whether petroleum is a mixture of li- 

 quids that can be accurately separated at differ- 

 ent boiling points, Dr. Parmelee (dentist) re- 

 marked that, making use himself of about 2,000 

 gallons of benzine a week, of sp. gr. of from 70 

 to 80 Beauine", he had found it very difficult 

 to free this entirely from naphtha by heat. Pe- 

 troleum dealers, he stated, have no other means 



of estimating the different qualities of oil than 

 the' heat test. Still there is no (?) dividing line 

 between the oils they can be obtained at al- 

 most any specific gravity, between certain limits. 



The apparatus, which cannot fail to be of 

 great value to those who deal largely in coal 

 or rock oils, or their liquid products, is now 

 to be had in New York. 



Acetylene. In his lecture already referred to, 

 Dr. Frankland mentioned the fact of the discov- 

 ery by M. Berthelot, within the past ten years, 

 of anew component in coal-gas, to which he had 

 given the name of acetylene, and for the produc- 

 tion of which, unlike that of the other gaseous 

 hydrocarbons, an intense heat is requisite. The 

 object had been, hitherto, to produce coal-gas 

 at a low temperature ; but now the question 

 was how far the production of this acetylene 

 on a large scale could be carried on. This 

 question is still in embryo ; but if successful 

 results are obtained, the influence on the future 

 manufacture of gas must be great. The lectur- 

 er exhibited the light of the new gas, as set free 

 by adding to acetylide of copper dilute chlor- 

 hydric acid ; and although the gas was burn- 

 ed as its excessive proportion of carbon ren- 

 dered necessary in only a very small jet, still 

 the intense brilliancy of the light it afforded 

 was decisively apparent. 



In his introductory address before the Brit- 

 ish Association, 1863, the president, Sir Wil- 

 liam Armstrong, referred to the subject of 

 acetylene. He mentioned the observation of 

 Dr. Odling, to the effect that the new gas may 

 be produced by mixing carbonic oxide with an 

 equal volume of light carburetted hydrogen, 

 and exposing the mixture in a porcelain tube 

 to an intense heat ; and the still more recent 

 observation of Mr. Siemens, who has discover- 

 ed that this gas is formed in the highly heated 

 regenerators of his furnaces. The lecturer de- 

 clared that there is now every reason to believe 

 the new gas will become practically available 

 for illuminating purposes. 



Artificial Fuel and Gas Material. Before a 

 meeting (Nov. 19th, 1863) of members of the 

 Franklin Institute, Phila., Prof. A. L. Fleury 

 exhibited samples of a fuel and gas material, or 

 basis, the invention of Mr. Win. Gerhardt, of 

 that city. A solid material, which is at once 

 fire-proof and porous, is made into bricks, balls : 

 or other desired shape ; and these are next, 

 made to imbibe gas tar, coal oil, or other simi 

 lar hydrocarbon, until saturated, and are then 

 dried. They can then be used as fuel, or dis- 

 tilled for illuminating gas. No ash results, and 

 the porosity is retained ; so that the masses 

 can be used again in the same manner. This 

 is proposed as a method of securing a fuel free- 

 from sulphur, for the manufacture of steel 

 iron, glass, etc. ; and it is said that it can bo 

 made to furnish a fuel cheaper than is coal, a'; 

 the prices now ruling. 



Methods of Gas Manufacture. In the CYCLO- 

 PAEDIA for 1862 were mentioned certain pro- 

 cesses for cajburetting more highly lighting 



