T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
Nov., 1 9 1 4
of t r u n c a t e d conical shape? open a t b o t h ends. T h u s prepared, t h e jacket' is placed over t h e crucible or dish t o be ignited, with t h e larger end down. The t o p is partly closed b y a porcelain crucible cover which can be easily adjusted t o secure t h e m a x i m u m a m o u n t of heat without unduly impeding t h e draft. Using a Tirrill burner of ordinary laboratory size, i t is possible t o convert even large amounts of calcium carbona t e t o t h e oxide. The crucibles i n which t h e ignitions t a k e place should be covered, b u t with t h e lid partly placed t o one side t o leave a small opening. Besides doing away with t h e necessity of compressed air, this method of ignition also avoids t h e strong air current of a blast lamp b y which small amounts of light precipitates m a y be lost. A platinum crucible, also, appears t o be less attacked t h a n when a blast lamp is used.
A transparent crystal of calcite was found on analysis t o have t h e following composition: CaCOs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MgC03 . . . . . . . . . . . . . . . . . . . . . . . . . . . . Silica . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Per cent 99.46
0.53 0.05 -
100.04
This would correspond t o a loss on ignition of 34.01 per cent. T w o samples of t h e same material were t h e n ignited, using t h e jacket a s described. Sample No. I consisted of I . 0 3 0 8 g. a n d after fifteen minutes ignition weighed 0 .j 7 7 9 g., or a loss of 4 3 . 9 j per cent. Sample No. z weighed I . 3 1 1 7 g. a n d after ignition for fifteen minutes yielded 0 . 7 3 5 1 g. CaO, or a loss of 4 3 . 9 3 per cent. I n neither case was there a n y additional loss on further heating.
X convenient size of assayer's crucible is t h e Denver Fire Clay No. 9 , which measures 3 inches in diameter a n d j1/2 inches high. If a clay ring piece of t h e same diameter as t h e assayer's crucible is available, i t m a y be advantageously used as a rest for t h e triangle t h a t carries t h e platinum or porcelain crucible containing t h e sample. This has t h e effect of extending t h e jacket below t h e triangle. The results quoted above, however, n-ere obtained without t h e use of such a , r i n g piece.
A CONVENIENT FORM OF WEIGHING BURETTE By H. S. BAILEY Received August 19, 1914
I n making a large number of determinations on various oils t h e writer at first a t t e m p t e d t o use Ripper weighing burettes. H e soon found, however, t h a t their weight a n d especially t h e necessity for providing some sort of rack for t h e m , when filled, made their use impracticable. As a result of numerous a t t e m p t s t o devise a suitable weighing burette, t h e one shown in t h e accompanying illustration, which can be placed directly upon t h e p a n of a n ordinary analytical balance, has been finally adopted. I t s construction is clearly shown b y t h e drawing in which t h e three ground joints are indicated b y s t i p p l e d areas. T h e b o t t o m cap serves both as a base t o support t h e b u r e t t e a n d as a catch-cup for a n y leakage. As t h e sample does not ordinarily come in contact with t h e t w o large ground joints, these need not be especially tight when t h e burette is used for homoge?eous non-volatile liquids. T h e small valve a t t h e t i p , which of course must be tight, can be readily made b y merely drawing down t h e end of a glass rod a n d grinding i t into place with a little carbor u n d u m a n d water. . When t h e burette is used for volatile substances or non-homogeneous mixtures which require frequent agitation, such as milk. a small rubber sleeve is slipped over t h e t o p of t h e stopper a n d rod, making t h e joint between t h e m air-tight. These burettes may, of course, be of a n y suitable size, t h e ones commonly used for weighing oil samples having a capacity of about 3 0 cc. A rough graduation greatly facilitates t h e weighing out of definite quantities of material for such determinations as t h e Reichert-LIeissl number, i n which i t is necessary t o use approximately t h e same weight of sample. FOODINVESTIGATION
BUREAUO F
S O I L S , %'.4SHI"GTOK
94 1
DEPARTMENT OF
LABORATORY,
BUREAU OF
AGRICULTURE,
CHEMISTRY
WASHINGTON,
D. C
SYMPOSIUM ON AMLRICAN DYE. INDUSTRY The XCew York Section of the American Chemical Society devoted its first regular meeting of the 1914-1915 season, on October 9th, a t the Chemists' Club, t o a discussion of the need and practicability of enlarging the production of dyestuffs in this country. The program was as follows: Introductory Remarks-Chairman Allen Rogers. Dyestuffs and the Textile Industry-J. hlerritt Natthews, Consulting Chemist to the Textile Industries. Campaign for American Dyestuff Industry-Arthur Prill, Editor Daily T r a d e Record, Mill hlan's Section. Coal Tar Colors in America-I. F. Stone, President Xational Aniline and Chemical Co. Needs of the Textile Industry-Alfred L. Lustig, Chairman of Dyestuff Committee, National Association of Finishers of Cotton Products.
All the papers presented are published in full below. After the reading of the papers, discussions were called for: thcse by David W. Jayne, of the Barrett Xanufacturing Company, Bernhard C. Hesse and I. F. Stone are printed in full herewith.--[E~~To~.] _ _ _ ~ _ _
INTRODUCTORY By
CHAIRMAN ALLEN
ROGERS
At the last meeting of the New York Section of the American Chemical Society, which was held in June of this year, we little dreamed that before another meeting practically the whole of Europe would be involved in the greatest struggle the world has ever known. Many of those who attended that meeting are a t present in the ranks of those great armies now engaged in deadly conflict. It is especially sad for us to think that perhaps some of our dearest friends, and members of this society, may be
