420
NOTES.
(4) Nuclei appear to be the principal exciting cause of crystal formation when other conditions are favorable. These nuclei are soap crystals or particles and possibly other substances. Experiments are now in progress in regard to this point. ( 5 ) S o t too great viscosity or this may overcome the crystallizing forces. Iiapid desiccation may entirely prevent crystal formation. ( 6 ) Shock produced b~7 blows or pressurc act favorably on crystal Formation in many cases. In conclusion, crystal formation, while it does not reduce in any degree the detergent poiwr of a soap, renders it more or less unsalable to i i public which buys according to the appearance of goods. 'l'he experimental work det:tiled above was undertaken it1 order to examine systcmaticall!- the causes of crystal forniation in transparent soap and to provide a remedy. I'III:\IIC.AI.
I , A I I < l R A l ' O H I I . : S 01.' s \ V J V T
&
c0
,
elllCA(?0
NOTES. Rupitl l l c f r i nun,utioiL oJ Ptdrolezim Nahlatha in :'urpenlinc----To dett,rrnine thc :+mount of pctroleuni naphtha in a suspected sample of ttirpentine, i o cc. are carefully ineasurcd into a 50 cc. carbon tube, which is graduated into tenths of a cubic centimeter. Thirty citbic centimeters of aniline are xiow added and the mixture violently s1i:ikcn for fi\.e minutes, and left to settle until the liquid has become perfectly clear, when, if there is aiiy petroleum naphtha present iii the turperitinc, it irill bc throlvn out of solution and Coat in a layer on top, and the percentage can be readily ascertained. I get escellcrit results from this method, but care must be exercised that the aniline HENRY C. FREY. does not contain any water. L S 2 I KEYSOI.DS
ST.$
R K I I ) E S I I ~ . R G , P H I I . % D R I . I ' lH ' \I. A , -.._._____
Dcdcrim'viution o j Sodiuiiz tznd Potassium in .Silicntes.-\i;e have found the following. method of determilling sodium and potassium in clay and silicates which call he decomposed by sulphuric and hydrofluoric acids, r'ipid and satisfactcjry. One gram of clay is deconiposed by nieans of sulphuric and hydrofluoric acids, and the escess of sulphuric acid expelled in a hot air bath. TIN: resitl~ir is then dissolyed in water and' powdered barium hydroxide added to the boiling liquid to alkaline reaction. 'l'he solution is decanted a ~ i dfiltered am! tlic resitluc boiled a,vairi with water and thoroughly w,ishccl. Carbon dioxide is passed into the filtrate in excess, the solution e\-,iporated to ,jO cc., ?,< ec. of alcohol (96 per cent.) added.
42 1
NOTES.
and the solution filtered and the residiic washed with 50 per cent. alcohol. A measured excess of N / I o hydrocliloric acid is then addcd t o the filtrate and the soliltion boiled to expel the carbon dioxide, litnius being used as an indicator and more acid being added if necessary, t o give a permanent acid reaction after boiling. The titration is then finished with N / I O sodiuiii hydroxide. 'l'hc solution is evaporated to dryness in platinum, dried a t 110' and fixtlly a t very faint redness and the residue of potassium and sodiiim chlorides weighed. The amount of each metal can be caIculated on the following principle: T,et a = No. of cc. of 'V/IO HCl uscd less the No. of cc. of N / I OKaOH. b = a x A 0.00 585 = weight of NaClequivalen t to sum of NaCl+ KCl. KCl formed less the weight of NaCl correc = weight of NaC1 sponding t o the weight of NaOH used. x = weight of Na. y = weight of K.
+
=
2.432
(C-11).
Three saniples of clay gave b y the above method: Na.
-K.--
0.14 0.53
0.i7 0.33
By Lnwrerice Smilh's method.
K.
X . . . . . . . . 0.76 E . . . . . . . . 0.33 c . . . . . . . . 0.18
I
'
3R
By t h e above method.
0
14
Na ,
0.14 0 . 45 I 42
J. E. THOMSEN. 1,ADORATORY OF J O S E P H DIXONC R U C I B L E '20.. J E R S E Y CITY, N. J .
7'lie Deter manuttou of Toto1 N t t r o q e n I n c h d z n g Nitrates 212 the PreJcnce of Chlorzdes.-Asboth, Jodlhauer and Scovell have modified the Kjeldahl nitrogen rriethod with the view of riiaking possible the deterinination of nitric nitrogeri siniultaneously with organic nitrogen. 111 the presence of comniori salt, however, these modifications, and also the method of the Official Agricultural Chemists (which is essentially Scovell's) are inapplicable; for the sulphuric acid used in the method x t s upon chlorides and nitrates producing hydrochloric and nitric acids and before the latter is rediieed to ammonia by the reducing agents present, the following re2 ct'ion occurs: HNO, T 3HC1 2H20 4- C1, 4- NOCl.
-
