Reagents & Reactions Known by the Names of Their Authors (Paperback)

Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: (2 g. fuchsin or 2 g. victoria blue, respectively) in 15 ccs. alcohol, and diluting the solutions with 85 ccs. water. Weissmann's acid mixture for dissolving iron samples consists of 10 volumes concentrated nitric acid, 2 volumes concentrated sulphuric acid and 10 volumes water. Ulzer and Briill also recommend the addition of a little concentrated hydrochloric acid while concentre ting. Welmann's reaction for vegetable fats. Reagent: 5 g. sodium phosphomolybdate are dissolved in water, treated with concentrated nitric acid and diluted to 100 ccs. Test: 1 cc. fat is dissolved in 5 ccs. chloroform and shaken for a minute with 2 ccs. of the reagent. In the presence of vegetable fats (cacao-butter excepted), a green color results which changes to blue upon addition of ammonia. Wender's test for glucose. See Neumann- Wender's test. Wenzel's reaction for alkaloids. These yield various colorations with a solution of 1 g. potassium permanganate in 200 g. sulphuric acid. Veratrine, e. g., yields first a light red, then an orange coloration. Weppen's veratrine reaction. If a small quantity of veratrine is mixed with about six volumes of cane sugar and then a few drops of concentrated sulphuric acid be added, a yellow color results, changing to green and finally to blue. ?Neumann- Wender employ instead of the sulphuric acid and cane sugar, a solution of furfurol in sulphuric acid. Morphine and codeine yield with either reagent unstable red colorations. Weselsky's reagent is nitric acid saturated at a low temperature with nitrous acid. Weselsky's reaction for phloroglucin. Upon adding toluidine nitrate and potassium nitrite to a phloroglucine solution, a light yellow color is first produced which gradually becomes opalescent, then orange, and finally cinnabar-red...