This paper makes the case that, because rabbits were understood to have a symbolic meaning in medieval theology, we might expect that some structures associated with their management should also be suspected of having some symbolic content. Such symbolism is clearly visible at the so-called 'Triangular Lodge' at Rushton, Northamptonshire, and a wider group of monuments, including certain English monastic pillow mounds, is reviewed. More widely, it is suggested, the symbolic meanings of managed animals should be understood and deployed during analysis of the structures and landscapes involved.

The temperature dependence of the rate coefficients for the OH radical reactions with toluene, benzene, o-cresol, m-cresol, p-cresol, phenol, and benzaldehyde were measured by the competitive technique under simulated atmospheric conditions over the temperature range 258-373 K. The relative rate coefficients obtained were placed on an absolute basis using evaluated rate coefficients for the corresponding reference compounds. Based on the rate coefficient k(OH + 2,3-dimethylbutane) = 6.2 x 10(-12) cm3 molecule-1 s-1, independent of temperature, the rate coefficient for toluene k(OH) = 0.79 x 10(-12) exp[(614 +/- 114)/T] cm3 molecule-1 s-1 over the temperature range 284-363 K was determined. The following rate coefficients in units of cm3 molecule-1 s-1 were determined relative to the rate coefficient k(OH + 1,3-butadiene) = 1.48 x 10(-11) exp(448/T) cm3 molecule-1 s-1: o-cresol; k(OH) = 9.8 x 10(-13) exp[1166 +/- 248)/T]; 301-373 K; p-cresol; k(OH) = 2.21 x 10(-12) exp[(943 +/- 449)/T]; 301-373 K; and phenol, k(OH) = 3.7 x 10(-13) exp[(1267 +/- 233)/T]; 301-373 K. The rate coefficient for benzaldehyde k(OH) = 5.32 x 10(-12) exp[(243 +/- 85)/T], 294-343 K was determined relative to the rate coefficient k(OH + diethyl ether) = 7.3 x 10(-12) exp(158/T) cm3 molecule-1 s-1. The data have been compared to the available literature data and where possible evaluated rate coefficients have been deduced or updated. Using the evaluated rate coefficient k(OH + toluene) = 1.59 x 10(-12) exp[(396 +/- 105)/T] cm3 molecule-1 s-1, 213-363 K, the following rate coefficient for benzene has been determined k(OH) = 2.58 x 10(-12) exp[(-231 +/- 84)/T] cm3 molecule-1 s-1 over the temperature range 274-363 K and the rate coefficient for m-cresol, k(OH) = 5.17 x 10(-12) exp[(686 +/- 231)/T] cm3 molecule-1 s-1, 299-373 K was determined relative to the evaluated rate coefficient k(OH + o-cresol) = 2.1 x 10(-12) exp[(881 +/- 356)/T] cm3 molecule-1 s-1. The tropospheric lifetimes of the aromatic compounds studied were calculated relative to that for 1,1,1-trichlorethane = 6.3 years at 277 K. The lifetimes range from 6 h for m-cresol to 15.5 days for benzene. (C) 1995 John Wiley & Sons, Inc.

The reactions of the 2-hexoxy radical and the 3-hexoxy radical have been studied in a collapsible Teflon bag reactor under conditions relevant to the atmosphere. The alkoxy radicals were generated either by the photolysis of the corresponding hexyl nitrite or by the OH radical initiated photooxidation of hexane. The hexoxy radicals were chosen as model species to examine the importance of alkoxy radical isomerization versus unimolecular decomposition or reaction with oxygen. The fraction of 2-hexoxy radicals undergoing isomerization was determined directly from the analysis of the 5-hydroxyhexan-2-one product. The fraction of 3-hexoxy radicals undergoing isomerization could only be determined indirectly. The formation of products proposed to be generated from the isomerization reaction channels was observed for the first time, including 5-nitrooxyhexan-2-ol from the reaction of isomerized radicals with NO. The approximate quantitative results confirm the predicted dominance of isomerization (greater than or equal to 68%) over other reaction pathways for longer chain alkoxy radicals. The results are compared with predictions based on kinetic estimations.

The products formed by the hydroxyl radical initiated photo-oxidation of diethyl ether have been investigated by irradiating synthetic air mixtures containing diethyl ether and nitrous acid in amounts approaching ppbv levels in a smog chamber. The decay of reactants and formation of products were monitored by gas chromatography, HPLC, and by chemiluminescent analysis. The major products are ethyl formate and formaldehyde, minor products include ethyl acetate, acetaldehyde, peroxyacetyl nitrate, methyl nitrate, and ethyl nitrate. The products observed arise from the decomposition reactions of the 1-ethoxyethoxy radical and its reaction with oxygen. One molecule of nitric oxide appears to be oxidized per molecule of diethyl ether reacted. This is lower than would be expected on the basis of the proposed mechanism and possible reasons for the discrepancy are discussed. (C) 1993 John Wiley & Sons, Inc.

The photolysis of dilute mixtures of HONO in synthetic air containing NO, NO2 and C2H5CHO has been carried out at room temperature and atmospheric pressure. Hydroxyl radicals from the photolysis of HONO initiate a short-chain reaction in which NO is oxidized to NO2 in reactions of the type RO2 + NO → RO + NO2 (R  C2H5CO, C2H5, CH3 or H). When R is C2H5CO, reaction with NO2 to form peroxypropionyl nitrate (PPN) competes with NO oxidation: From measurements of the rates of formation of NO, NO2 and PPN in a flow system with short contact times, kinetic information has been derived for the reactions which occur following the attack of HO on propionaldehyde: A kinetic analysis of the results yielded the ratio k7/k8 = 1.9 and k5 ⩽ 2.6 × 10−11 cm3 molecule−1 s−1 based on the value kHO + HONO = 6.6 × 10−12 cm3 molecule−1 s−1.