No. 10.-A new unwashed grade; specially thin and adapted to retain finest precipitate s Nos. 1-5-Ordinary Grades for qualitative work. Nos. 30-31-Single Acid Washed-of close texture-fast and medium filters. Nos. 40-44-Double Acid Washed-" Ashless "- Very accurate. FOLDED FILTERS. BLACK FILTERS. FILTER CONES, &c., &c. SOLE MANUFACTURERS: W. & R. BALSTON, LTD., MEDWAY MILL, MAIDSTONE, KENT. FIND OUT ALL ABOUT OUR COMPLETE RANGE FROM OUR REVISED BOOKLET AND FRICE LIST. In case of difficulty in obtaining Free Samples, write the Sole Mill Representatives- FOUNDED 1792. CHARLES TENNANT & Co. LIMITED. EXPORTERS and IMPORTERS. We invite enquiries for all classes Hydrochloric), ALKALI: POTASH (Caustic and 93, WEST GEORGE ST., GLASGOW. CHEMICAL APPARATUS Pure Chemicals for Research Work. JOHN J. CRIFFIN & SONS, LTD., KINGSWAY, LONDON, W.C. LABORATORY GLASS WARE. Wood's Resistant Glass. ILLUSTRATED PRICE LISTS WILLIAM TOOGOOD, Limited, 77, SOUTHWARK STREET, S.E.1. THE CHEMICAL NEWS. VOLUME CXXIII. EDITED BY JAMES H. GARDINER, F.C.S. No. 3194.-JULY 1, 1921. p (C5H12 273 2.682 0'512 C.H C,H1. 298 2.683 0'504 5°32 CHI 5°27 345 2.767 C.H20 298 2.638 CH22 0'498 5:28 4.67 C12H26 298 298 CHO 298 2.590 o'497 298 CH,. 298 5.20 5.20 2.53 CH10 C.H. (solid) C.H. (liquid) C.H. (liquid) 5°22 I. 368 1733 O'427 4:06 Conclusions. The paraffins (saturated hydrocarbons) are highly but almost equally polymerised near their boiling-points. 2. The unsaturated hydrocarbon, amylene, is much less polymerised than the corresponding paraffin, although it has two free bonds, which would, one would have thought, have given it additional associative power. Compare C‚H, and CH2 3. Benzene and naphthalene follow the phosphorus curve at their melting points. 4. The introduction of more hydrogen into the benzene ring, i.e., the saturation of an unsaturated compound, still further raises (c.f. C.H. and C.H12). 5. The introduction of a side chain, e.g., 521 CH,, hardly affects, but naphthalene slightly more polymerised than benzene. 6. From the graph it will be seen how much more rapidly p (for naphthalene) falls in the solid than in the liquid state. 1.82 C.H. (liquid) 293 1.791 O'423 4:23 323 1.838 308 1.2585 0'3252 Conclusions. The introduction of a halogen either into a saturated, unsaturated, or ring compound has the effect of reducing p, and the more complete the substitution of hydrogen the lower does become (compare C.H, and C.H.C1; C,H,Br and C,H,Bг2). 2. In some cases there is a rise in the value of with temperature, e.g., CHCI, and CC1, (compare H2O). 3. The polymerisation curves for C2H,I, C2H,Br, and C2H,Cl, are practically horizontal. It almost looks as if the specific heat of C,H,Cl was inaccurate, as the polymerisation curve for this compound should be above, and not below, that of the corresponding bromine compound. Compare the results for C,H,Cl, and C2H ̧Bг2. See Fig 5. 1. 303 2.383 O'547 4:35 Conclusions. On substituting an organic radicle for one of the hydrogen atoms in water, p is considerably increased. 2. On graphing against absolute temperatures it will be seen that the curves of methyl, ethyl, propyl, butyl, and amyl alcohols are almost parallel to each other, especially in their latter portions, so that at any temperature common to all curves the increment in the value of due to =CH2 is maintained. As we mount the series, the more polymerised is the alcohol at the meltingpoint; but at their boiling-points the values of pare all approximately equal to 3+, compared with 2 for water, and p=4+ for ether. Thus, = C2 H5 Cl? C2 H4 CL2 TEMP Methyl The results for the alcohols are given in Table IX. Alcohol 3 NEWS 4. The effect of substituting a second organic radicle in the water molecule (e.g., to form an ether) still further accentuates the above changes. The effect of introducing the hydroxyl 5. group into the benzene ring or the side chain of an aromatic compound is to reduce (compare with Nos. 1 and 4). 6. Glycol and glycerin are not so highly associated at the boiling-point as methyl alcohol, the first of the monohydric alcohols; neither are they so highly polymerised as the hydrocarbons from which derived. C.H.CO.C.H (solid) 234 1.214 0'2300 5:28 (solid) 295 1.257 0'3051 4.12 (liquid 295 1°532 0.3825 4'00 TABLE XIII. ... 273 3.64 283 4:35 3.48 1. Formic and acetic acids, and probably the other members of the series, too, follow the phosphorus curve on melting. 2. As we ascend the series there is a rise in the value of p, coinciding with an increase in the percentage of carbon (the most important polymerising element present) from 26 per cent in formic to 54 per cent in butyric acid. 3. For the acids included in this table, is less than for the corresponding hydrocarbons from which they are derived, which contain much more carbon. A few nitriles are dealt with in Table XI. T ST S bs |