Care of Laboratory Ironwork 135 



sold by Hobbies, Ltd., Dereham, Norfolk. This appears to 

 be a superior kind of Berlin black, quite different from the 

 ordinary Brunswick black, in that it has quite a remarkable 

 11 covering " capacity, and that it dries almost instantly to a 

 hard matt surface, clean and serviceable in every way. 

 Certainly it burns off when heated, but in doing so, it 

 produces no offensive smell, and is no inconvenience in 

 any way. 



For ironwork which is subjected to water-splashes, 

 Eggshell black is not so suitable, as it shows stains and dirt 

 rather badly owing to its colour, though it is easy to give 

 another coat from time to time. The paints supplied by 

 the Metallic Compositions Co., Ltd., of Gray's Inn Road, 

 London, are excellent in such cases the most suitable, per- 

 haps, being the aluminium paint which is able to withstand 

 the action of either heat or water. In our own laboratory the 

 special composition made to withstand heat has proved able to 

 withstand acid fumes equally well, and a good deal of iron- 

 work is coated with this composition in consequence ; an 

 instantaneous water heater with gills and brass tubes being 

 coated with the composition, and being as good now after 

 eighteen months' duty as the week after it was put on. There 

 is some slight odour when first the gas is lighted, and some 

 dulling of the appearance, but after this little alteration appears 

 to take place, and a composition that will resist the heat of the 

 gas flame, and preserve its cleanly appearance above a large 

 sink in a constant atmosphere of fumes and moisture has much 

 to recommend it. 



The same firm markets a preparation of a similar nature 

 of the colour of gunmetal, and this may be painted over 

 laboratory water-taps and similar gunmetal fittings, with 

 advantage to their appearance if they have been allowed to 

 become corroded, or are past burnishing and polishing. A 

 really smart appearance may be given to an old laboratory by 

 the use of a few shillings' worth of the above preparations, the 

 only difficulty is that science teachers, as a rule, have no time 

 to deal with these matters, and that a laboratory attendant, 

 where present, frequently lacks the skill and pride necessary 



