276 



HARDWICKE'S SCIENCE-GOSSIP. 



may prove to be the var. crepitans, Schubl. I have 

 found Trigonclla polycerata at York, and T. hamosa 

 at Birkenhead. Medicago sativa, a waif of cultiva- 

 tion, at Northallerton, and M. maculata, Sibth., at 

 York, and by the canal at Aintree. A few plants of 

 M. apiculata, Willd., grew with the latter at York. 

 Melilotus alba, Desr., grows in profusion on Foss 

 Islands at York, and on ballast-heaps at Hunslet and 

 Fazakerley (Lanes.) ; the yellow-flowered M. parvi- 

 flora, Lam, being equally abundant at York and 

 Aintree. M. carulea, L., occurred sparingly at 

 York only. These species of Melilotus appear to 

 grow very freely where introduced, so long as com- 

 petition is limited, but they gradually disappear 

 before stronger native weeds. Trifolium hybridiim 

 is a common casual, being frequently cultivated. 

 Ornithopus compressus, L., a few plants only at York 

 and Walton (Lanes.). Vicia sativa, L., frequent, 

 Leeds, Scarborough, &c. Potentilla norvegica, L. , 

 well established and ineradicable by the canal from 

 Hunslet to Woodlesford. CEnothera biennis has 

 obtained a permanent footing on the Lancashire 

 sandhills about Crosby and Hightown. Caucalis 

 latijolia, L., nearly a score of plants as weeds in 

 garden-ground at Walton, accompanied by a single 

 plant of C. daucoides, and a few specimens of Torilis 

 nodosa. Ammi majus, a solitary but fine plant at 

 Aintree by the canal. Aster brumalis, on ballast 

 at Hartlepool. Chrysanthemum coronarinm and C. 

 segetum, in some profusion on ballast at Hunslet. 

 C. parthenhim, L., is a frequent garden-escape in 

 many localities. Silybum marianum, long known on 

 the Castle Hill, Scarborough. It never grows pro- 

 fusely, and often fails to appear for a year, but still 

 does not altogether disappear. Centaurea melitensis, 

 native of S. Europe, is a common casual at York, 

 Leeds, and Huddersfield, but in our climate does not 

 flower freely ; frequently the buds never open at all. 

 It is often mistaken for C. solstitialis, L, which 

 bloomed well on ballast at Aintree this season. 

 Anagallis cccrulea, Schubl., sparingly at York ; and 

 what appears to be blue-flowered A. arvensis, on 

 rubbish near Aintree. Amsinckia lycopsoides, Schm., 

 a frequent wool-waste plant, has occurred about 

 York, Leeds, and Liverpool. Datura stramonium 

 and Hyoscyamus niger grew together at Aintree, and 

 the latter has also been found at Northallerton. 

 Linaria cymbalaria is thoroughly at home on walls 

 overlooking the Ouse at York, where it hangs in 

 luxuriant festoons. Verbascum virgatum, a few plants 

 at Northallerton, without permanence. Mimuhis 

 lutcus, in the bed of the river Yore in Wensleydale. 

 Mentha viridis, L., is with us always a garden-outcast, 

 the least suspicious locality being Forge Valley, near 

 Scarborough, a long way from any house. Lconurus 

 cardiaca, L., on the slope of the Great Orme's 

 Head, towards Llandudno. Plantago arenaria, W. 

 and K., very fine on ballast at York, with Amaranthus 

 blitutn, Chenopodium opulifolium, Schr. , C. rubrum. 



C. vulvaria, and C. glaucum, the latter, I believe, a 

 permanent integer of the York florula. Spinacia 

 oleracea, L., casually where manure had lain at 

 Scarborough. Rumex dentatus, Camp., a native of 

 south-east Europe, fairly plentiful on ballast at York. 

 Rumex alpinus, L., very fine by a roadside near 

 Horsforth, Leeds. Asphodelus fistulosus, L., incon- 

 siderable quantity in two places about four hundred 

 yards apart at York, in both situations with Setaria 

 glauca, Beauv., and S. viridis, Beau v., the latter 

 also growing by the canal at Hunslet. Panicum cms- 

 galli and P. glabrum, Gaud., both grain-brought at 

 York. Phalaris eanariensis may be found on heaps 

 of refuse everywhere where birds are kept. Glyccria 

 dislans, Bromus arvensis, L., and Lolium italicum, 

 Braun, all three abundant on ballast at both York 

 and Leeds. I have seen all the above in situ, and 

 have specimens of nearly all preserved in my 

 herbarium. It will be seen that although many of 

 our rare plants are threatened with extermination, 

 our flora is being reinforced by fresh varieties. Per- 

 haps most of the above are evanescent, and will 

 disappear without trace, beyond a few specimens in 

 herbaria, but it is evident some at least will hold 

 their own in the fight for existence, which they will 

 have to wage with our native weeds. 



In conclusion, I must state that I am much in- 

 debted to Mr. Baker, of Kew Herbarium, for kindly 

 determining many of the above plants, some of which 

 are hereby first recorded for the vice-counties in 

 which the localities are situated. I have also received 

 welcome aid on several occasions from Mr. Arthur 

 Bennett and Captain Steuart, which I beg to ac- 

 knowledge here. 



J. A. Wheldon. 



SCIENCE-GOSSIP. 



The " nitro-metals" are a new class of compounds 

 recently discovered by Sabatier and Senderens. 

 They have found that reduced copper absorbs, in the 

 cold, the vapours of nitrogen peroxide, heat being 

 disengaged during the process. The product is a 

 maroon-coloured compound, the composition of 

 which is represented by the formula, Cu 2 N0 2 . This 

 is nitro-copper. A similar compound has been 

 obtained with cobalt. Nitro-copper reacts violently 

 with water, giving off nitric oxide and yielding a 

 green liquid containing copper nitrate mixed with a 

 little nitrite. A residue of almost pure copper is 

 deposited at the same time. 



The popular idea that water is purified by freezing 

 ■has been again disproved by recent careful ex- 

 periments, which show that the average amount of 

 impurity retained by the ice is 34'3 per cent, of 

 organic matter, and 21 • 2 per cent, of inorganic 

 matter. As organic matter is the more objection- 



