Febeuaky 11, 1898.] 



SCIENCE. 



187 



true spirit, I hope, try to magnify a little 

 the field of analytical work. 



To my mind, then, it is just and proper 

 to take pride in analytical chemistry, be- 

 cause of the power which a properly con- 

 ceived and executed analysis has of explain- 

 ing difficulties. A few illustrations will, 

 perhaps, make this point clear, and I am 

 sure I shall be pardoned for giving illustra- 

 tions from my own experience, rather than 

 historical ones. 



Some years ago, after a passenger coach 

 on the Pennsylvania Railroad had been 

 through the hands of the car cleaners, it 

 was noticed by some of the officers that the 

 paint on the outside looked very badly, and 

 had apparently been injured by the clean- 

 ing. A careful examination by the paint 

 experts revealed the fact that the varnish 

 was nearly all gone, and in some places the 

 paint itself partially removed. As a matter 

 of discipline, the car cleaners were called 

 to accoiint, and requested to explain why 

 the paint and varnish had been so badly 

 injured. Their reply was that with the 

 soap that was furnished for car cleaning no 

 better results could be obtained. This 

 statement was, of course, received with a 

 gTain of allowance, it being well known to 

 railroad operating officers that almost uni- ' 

 versally when anything goes wrong, and 

 the men are called to an account, the ma- 

 terials are blamed. However, in order to 

 give the men the benefit of the doubt, a 

 sample of the soap was obtained and sub- 

 mitted to analysis, when it was found that 

 this soap actually contained over three per 

 cent, of free caustic soda and about seven 

 per cent, of sodium carbonate. It is evi- 

 dent that this soap had been very carelessly 

 made from cheap materials, and, since it is 

 well known that water solutions of both 

 caustic and carbonated alkalies are fairly 

 good solvents for dried linseed oil and other 

 constituents of paint and varnish, it is clear 

 that the defense of the men, in this case at 



least, was legitimate and that the soap was 

 really at fault. It may be added, for infor- 

 mation, that the circumstances above de- 

 scribed led to the preparation 6f a specifica- 

 tion for common soap, in which the amoixnt 

 of free and carbonated alkali was limited to 

 very low figures, and that no similar diffi- 

 culty of destruction of paint and varnish 

 has since occurred. 



Another illusti'ation from a different field 

 will emphasize the power of an analysis to 

 explain difficulties. A lot of boiler-plate 

 was at one time received at the Altoona 

 shops from one of the best makers. In this 

 lot of forty or fiJty sheets two were found 

 which gave difficulty in flanging, this opera- 

 tion consisting, as is well known, in bending 

 over the edges of the sheets while hot, 

 nearly at right angles to the balance of the 

 sheet, in order to enable it to be joined to 

 other sheets in the boiler. The two sheets 

 referred to cracked in the bend, although the 

 remainder of the lot gave no difficulty from 

 this cause. The workmen being thoroughly 

 experienced, and the practices of the shop 

 being excellent, the cause of the failure in the 

 case of these two sheets was not apparent. 

 An analysis of samples from each of these 

 sheets, however, showed 0.35 per cent, and 

 0.36 per cent, of carbon respectively, while 

 analyses of samples from other sheets in the 

 same lot showed in no case above 0.12 to 

 0.15 per cent, of carbon. The explanation 

 of the difficulty seemed now quite clear. 

 The shojjs had been supplied for a long 

 time with the softer grade of steel, and the 

 methods and practices in use were those ap- 

 plicable to that kind of steel. ISTo wonder, 

 then, that with the harder grade difficulty 

 should arise, as actually happened, and but 

 for the analysis this might have passed into 

 shop traditions as one of those unexplained 

 and unexplainable crotchets of steel which 

 both the makers and practical users of this 

 metal delight in constantly bringing for- 

 ward. 



