288 



SCIENCE. 



[N. S. Vol. II. No. 36. 



work been added to the sum of human 

 knowledge and what an impetiis has it 

 given to the advancement of science ! The 

 industries demanded relief from their losses, 

 but the path to that relief is strewn with 

 facts which have been utilized for the estab- 

 lishment of new principles ; and the new 

 principles, extended to the other industries, 

 have widened still further the field and led 

 to the studjr of the products developed in 

 the growth and nutrition of the lower or- 

 ganisms with results the spread of whose 

 influence it would be difficult to define. 



Some of us will remember that a little 

 more than a decade ago many of the lead- 

 ing chemists of this country were called 

 upon to settle a commercial dispute in 

 Chicago, turning upon the question of an 

 admixture of fats in the adulteration of 

 lards and that, on account of the lack of 

 knowledge then prevailing regarding the 

 exact constitution and reactions of various 

 fats, it was impossible to arrive at satisfac- 

 tory conclusions with regard to the mixtures 

 submitted. It was embarrassing for chem- 

 ists to admit the weakness, but it nevei'the- 

 less had useful results. Since that time the 

 development of knowledge concerning these 

 products has been such that it is possible 

 readily to determine in many cases, not 

 only the components of such admixtures, 

 but even the quantitj^ of each component 

 present. 



Such illustrations in increasing numbers 

 will occur to every one who may consider 

 the history of the science and the industries 

 from this point of view. The coal tar color 

 industry, which has so frequently been 

 cited and described as the direct outcome 

 of scientific investigation, will serve ad- 

 mirably to illustrate further the relations 

 we are considering. ISTo one of the in- 

 dusti'ies has been so rapid in growth or has 

 attracted the same degree of attention from 

 both scientists and technologists, or has had 

 so wide an influence upon the progi-ess of 



the other industi'ies and scientific work. A 

 brief review of the conditions of its devel- 

 opment from the standpoint of this dis- 

 cussion will be of interest and will serve to 

 show how much the purely scientific side of 

 chemistry may be found to owe to the de- 

 velopment of the technical side. 



The origin of the crude product of this 

 industry, the manufacture of gas, is com- 

 parativelj^ modern. Though it was kno-RTi 

 in the latter part of the last century it did 

 not find extensive aj)plication permanently 

 until between 1830 and 1835. But from 

 the time of its first extended application, 

 its by-product, tar, became a troublesome 

 nuisance and many endeavors were made 

 on all sides to find some means for its dis- 

 position and utilization. It was consumed 

 by burning, it was boiled down in open 

 vessels and its residues used as preserva- 

 tive paint for wood and metals ; its lighter 

 and more volatile products were subse- 

 quentlj' collected by condensation and put 

 upon the market as a solvent for fats, 

 waxes, rubber, etc., and this was used in the 

 manufacture of varnishes. According to 

 Lunge,* Accum was the first to boil tar 

 down in close vessels and thus obtain vola- 

 tile oil which could be used as a cheap 

 substitute for turpentine. Dr. Longstaff 

 declares that, in conjunction mth Dr. Dais- 

 ton, he erected the first distillery for coal 

 tar in 1822 near Leith, and that the spirits 

 obtained were sent to Mr. Mackintosh, 

 while the residvie was used for making 

 lampblack. Roscoe states that the distilla- 

 tion was carried on near Manchester in 

 1834, the naphtha obtained being used for 

 making black varnish with the pitch. So 

 that the lighter distillates had been fur- 

 nished to the markets some years before 

 Mansfield began, in 1847, the distillation of 

 the lighter oils to obtain products which 

 might be used for lighting purposes. It 

 was in the course of this work that he de- 



* Luiige. Coal Tar and Aniinouia. 189. 



