ely dissolve, the sol" was decanted, and a little dilute HCl poured smelt. Added a little strong HCl, boiled as long as any smell of sol and mixed it with the water sol" which had been proved gas, filtered : was pink (prob. pres. of Co.). ed some strong HNO3 and boiled to dryness (the colour of the soln. changed to light-brown med the residue with HCl, it dissolved completely (Abs. of H2SiO3). To a small portion of ned: no pp.: Absence of (PO4)". To the remr. added AmCl then excess of AmHO, and trate was again pink (presence of Co): added much Am2S and boiled, filtered: Filtrate was yellow (Absence of Ni): added Am2CO3, filtered: EXAMN. OF PP. IN GROUP III. B. Rinsed the pp. off the filter with some cold dilute HCl, stirred well, filtered: 1. Exam" by Flame-col".-Dissolved a small quantity of the pp. in a few drops of HCl upon a watch-glass, dipped a loop of platinum-wire into the sol" and held it in the Bunsen flame: a crimson-red colour was imparted to the flame, which appeared intense red through the indigo-prism: Pres. of Sr. This coloration was followed by a yellowish-green very persistent col"; Presence of Ba. 2. Exam" in the Wet Way.-Dissolved the rest of the pp. in as little boiling HA as possible; to a small part of the solution, perfectly cool, added CaSO4 sol"; an immediate pp. formed: Pres. of Ba. To the remainder of the HÃ sol" (proved to be acid to litmus) added K2CrO4 until the liquid appeared yellow, warmed and poured through a double filter: Pp. which contained all the Ba present, was re jected. To the clear filtrate (which was orange-red in colour) added Filtrate was re- Pp.: dissolved in as little boiling HÃ as possible; added to a small portion of the soln.CaSO4 soln. and boiled, a pp. formed, showing pres. of Sr. To the remainder of the HA solution added H2SO4, boiled, filtered, and to the filtrate (which gave no pp. after being boiled with more H2SO4) added AmHO in excess and Am2C204, no Abs. of Ca. pp.: EXAM OF FILTRATE FROM GENERAL TABLE FOR GROUP V. Evaporated the filtrate to dryness in a porcelain dish, scraped out the residue upon platinum-foil, and ignited strongly until white fumes ceased to appear: dissolved the residue off the foil by boiling with water to which several drops of HCl had been added, divided the sol into two unequal parts: To the larger portion added several drops of H2SO4, then AmHO in excess and several drops of Am2C2O4, on heating a slight pp. formed; filtered, and added to the clear filtrate Na2HPO4, a white crystalline pp.:Pres. of Mg. Into the smaller portion dipped a loop of platinum-wire, and held it in the Bunsen flame, an intense yellow coln.:Pres. of Na, appearing violet through the indigoprism: Pres. of K. Confirmed the pres. of K by stirring a Metals found :-Cu, Fe, Co, Ba, Sr, Mg, Na, K, NH. 492. EXAM FOR ACID-RADICLES. The following acid-radicles have already been detected: (CO)", (NO)', (C10)'. By reference to the Table of Solubilities (455), under the columns corresponding to the above metals, the only salt insoluble in acids is found to be BaSO4; since Ba is present, and the substance is entirely soluble in acids, (SO4) is absent. The following acid-radicles have also been proved to be absent in the general examination for metals :(Cro)", by the HCl solution not becoming green on passing H2S. (ASO)"" and (AsO4)"", by no pp. forming in Group II. B. (SiO)" and (SiF)", by no residue insol. in HCl remaining on evaporating to dryness with HCl for Group III. a. (PO4)", by testing with AmHMOO, in the HCl sol" for Group III.A. 4 The organic acid-radicles A and T are absent, since there was no smell of burning on heating the substance. The only commonly occurring acid-radicles remaining to be specially tested for are therefore Cl, Br, I, (C2O4)", and (BO)""; and of these Br and I are probably absent, since no violet fumes of I or brown fumes of Br were evolved with strong H2SO4. Boiled a portion of the substance with pure Na2CO3 sol” and filtered; acidified portions of the filtrate with— Added AgNO3, a perfectly white Added CaSO4, no pp. :— pp., easily sol. in AmHO: : Abs. of (C204)". Pres. of Cl. Moistened a piece of turmeric-paper with HCl sol of the substance and dried at 100°, no brown stain produced: : 493. Found Abs. of (BO3)". Metallic-radicles: Cu, Fe, Co, Ba, Sr, Mg, Na, K, NH. Acid-radicles: CO2, NO3, CIO, CI. SECTION VII. APPARATUS, REAGENTS, &c., REQUIRED FOR THE FOREGOING COURSE. LIST OF APPARATUS REQUIRED BY EACH STUDENT. 494. The following list is so arranged that: Division I. contains all apparatus which is required only for the experiments given in Section I. Division II. is apparatus required both for Section I. and for the Sections on Analysis. Division III. is apparatus used only in Analysis. Hence a student intending only to perform the experiments in Section I. will require the apparatus in Divisions I. and II. If he is omitting this portion and intends only to work through the Sections on Analysis, he must be furnished with the apparatus in Divisions II. and III. and will not require that in Division I. Note.—Apparatus contained in large brackets [] is useful but not indispensable. DIVISION I. (See also the note at the end of this list.) 1 Wide-mouthed, stoppered, white glass gas jar; about 24 oz. capacity, and 2 inches inside across the neck, whose upper edge should be ground so as to be closed with a ground glass plate. 1 Small flanged cylinder, 6 inches in height, 11 inches internal diameter, ground at the edge. 1 Deflagrating spoon, brass cap 2 inches across. 1 Small two-necked Woulffe's bottle, not less than 4 oz. capacity; or a small wide-necked bottle of not less capacity. |