if properly managed. For wrought iron and steel, use hydrochloric acid and water. (13) W. F. E. asks: 1. How are bath bricks made? A. Bath bricks are fonnd native as minerals, and are imported from England. 2. How are papier mache ornaments moulded, and where can I pro cure a work on the subject? -A. We can send yonSpons' .. Workshop Receipts " for $2.00, fi rst series, which con tains fnll information on papier mac he. See also va rious articles ill SCIENTIFIC AMERICAN SUPPLEMENT on the

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... ogy of the paper trade. (14) W. M. S. asks how to make liquid glue. A. Take a wide mouthed bottle, and dissolve in it 8 ounces best glue in � pint water, by setting it in a vessel of water, and heating until dissolved. Then add slowly 2).9 ounces strong nitric acid 36° Baume, stirring all the while. Effervescence takes place, with gene ration of fumes. When all the acid has been added, the liquid is allowed to cool. Keep it well corked, and it will be ready for use at any time.