SUNDRY APPLICATIONS OF CASEIN. 145 



Paper of this kind possesses the advantage of great eco- 

 nomy in use for schools and designers. In drawing plans, 

 for instance, the design can be easily and rapidly removed 

 with a damp sponge, and a fresh drawing made at once on 

 the same sheet. Such paper forms an excellent substitute 

 for the heavy slates used in schools for writing and drawing 

 lessons; and is highly advisable for this purpose, inasmuch 

 as it can be made in colours that wilJ not fatigue the eye. 



Nevertheless, it cannot be denied that repeated writing 

 and washing soon wears out the protective coating, and that 

 the sheets will not last very long, especially under the heavy 

 wear to which they are subjected in school work. 



PAPER WRAPPERING FOR FOOD, CLOTHING, ETC. 



The customary practice of protecting clothes from the 

 ravages of moths and other insects by bestrewing the articles 

 with naphthalene, camphor, pepper and so forth when they 

 are laid away for some time, is attended with numerous in- 

 conveniences, especially on account of the unpleasant smell 

 of the substances in question. These can be avoided by the 

 use of paper or linen prepared by a simple process in such 

 a manner as to permanently resist insect attacks, and also 

 atmospheric influences, so that they may be used in packing 

 goods destined for consignment to a distance. 



The process itself is principally based on the well-known 

 disinfectant properties of formaldehyde, and on its capacity 

 for forming a waterproof coating with the aid of casein. 



Hence, if paper and similar materials or finished articles 

 made from same, such as bags, wrappering, and the like, 

 be soaked in a warmed solution of casein, which contains 

 an admixture of wax, soap, caoutchouc solution, etc., for 

 giving increased flexibility, and these impregnated articles 

 be then dipped in a solution of formaldehyde, they will be- 

 come covered with a thin film. So long as this is moist, 



10 



