324 



SCIENCE 



[N. s. Vol. XXVIII. No. 715 



ical appearance and properties of these 

 common products as they exist in com- 

 merce, so that he may recognize it at a 

 glance if a mistake in the kind or quality 

 of material has been made, before this mis- 

 take has cost his fii'm a considerable sum of 

 money. Such mistakes Tvill occur so long 

 as purely human agencies handle chem- 

 icals. One of the most ludicrous ones that 

 has recently come to my attention was a 

 case where a consignment of soft soap was 

 delivered on an order for thick silicate of 

 soda. 



Of coui-se, it may be urged that the 

 chemist can acquire all this information 

 after he has left, the univereity. and this is 

 readily granted. But the acquiring of the 

 knowledge outside is usually tedious and 

 difficult and only accomplished after the 

 chemist has been repeatedly subjected to 

 mistakes and embarrassment due to his 

 ignorance. Then, too, many of us believe 

 that chemistry is a profession, and if so it 

 is as essential for the chemist to be famil- 

 iar with the present situation and rela- 

 tive importance of the materials with which 

 he has to deal, as it is for the physician 

 or lawj^er in his profession. 



If the functions of the chemist, the engi- 

 neer, the business man and the manager 

 could be sharply divided ia chemical manu- 

 facture so that the chemist would not be 

 asked any questions excepting those which 

 fall entirely within the tield of pure chem- 

 istry, the demands on his training and in- 

 formation, of course, would be much 

 smaller and the reward of his labor's would 

 be correspondingly decreased. 



The next place where the young chemist 

 is usually most ignorant and most in need 

 of assistance to my mind is in his knowl- 

 edge or lack of knowledge of materials of 

 construction and their comparative ability 

 to resist the action of common chemicals. 

 In his university work beakei*s and flasks 

 and test-tubes and porcelain and platinum 



dishes, and rubber and glass tubing have 

 always been available and have usually 

 been adequate in size and quality for aU 

 his purposes. As soon as he enters chem- 

 ical industry other materials must be 

 sought more durable than glass and less 

 costly than platinum. What accurate in- 

 formation does he possess regarding the 

 comparative merits of cast iron, wrought 

 iron and steel, for example, in resisting the 

 action of caustic soda solutions, of sul- 

 phuric, hydrochloric or nitric acids, 

 chlorine, sulphur dioxide or sodium car- 

 bonate solutions. "Wlere are copper and 

 brass and lead necessary or permissible. 

 "^Vhere can he use Portland cement or 

 Pecora cement, or silicate of soda or fire 

 clay or ordinary mortar in making tight 

 joints or linings. 



To illustrate take the metal copper. It 

 is most valuable in making stills and con- 

 densers for wood alcohol, acetone, acetic 

 acid, turpentine, etc., and its aUoy brass is 

 extensively used in valves. Yet its use 

 often leads to serious difficulties. 



For example, I have seen iron drums to 

 be used for shipping aqua ammonia in 

 which the inside seams had been brazed, 

 and bottling machines for use in bottling 

 ammonia solutions containing brass parts 

 exposed to the liquor. In both eases the 

 final products, of course, were beautifully 

 colored but unsuitable for the market. 

 Similarly I have seen both copper and 

 brass work placed in position where they 

 would be continuously exposed to acetylene 

 containing its ordinary impurities, am- 

 monia, phosphine, etc. 



In aH these eases there were chemists in 

 charge. They probably knew in a gen- 

 eral way something about the action of 

 ammonia and acetylene on copper and 

 copper alloys, but their information was 

 not indexed in their brains under the head 

 of materials of construction. 



Take again the case of sulphuric acid, 



