64 



KNOWLEDGE & SCIENTIFIC NEWS. 



[Mar., 1905. 



ordinary that these two species should be so widely separated 

 geographically — one in eastern North America and the other 

 in West China. In his " Sylva of North .\merica," Sargent 

 says that the genus was represented by several species in the 

 Cretaceous age, which were widely distributed in North 

 America and Europe. It continued to exist during the 

 Tertiary period, with a species hardly different from /,. tidij'i- 

 fera, extending over eastern North .America and Europe as far 

 south as Italy, until the advent of glacial ice destroyed it in 

 Europe. It may be remarked that the .American Tulip Tree 

 furnishes the well-known whitewood, a light, easily worked 

 wood often used in electric light installations. A remark- 

 able variety of the Mahogany Tree is figured. The specimens 

 shown were in the seedling state, and had grown only six to 

 ten inches high when flowers were produced. Several plants, 

 among them the common oak, sometimes behave in the same 

 manner. 



« » » 



One would scarcely expect to find the original description of 

 a new plant in the "Geographical Journal." There is one, 

 however, in the February number, where a remarkable new 

 Alga, named Ckmcntsxa, in honour of the President of the 

 Royal Geographical Society, is described by Mr. George 

 Murray. An unusual amount of interest is connected with 

 this tiny plant. It was the first new organism discovered on 

 the Antarctic expedition sent out under the command of Cap- 

 tain Scott. Curiously, though a marine Alga, its nearest 

 known allies arc found in fresh water, and it reminds one, on 

 looking at the plate furnished with the description, of a 

 Glteocapsa. The material was collected by Mr. Murray him- 

 self off Brazil, lat. 7" - 12° S., long. JO" - 33° W. The name 

 selected is unfortunate, as Ctementsia is already pre-occupied, 

 having been given by Dr. Rose, of the U.S. National Museum, 

 to a Crassulaceous plant, formerly described as a Sciiiiiii. 

 This CUmentsia is commemorative of Professor F. E.Clements, 

 of the University of Nebraska, and if a valid genus the name 

 should remain, while the Alga will have to be provided with a 

 new one. 



« * • 



Monsieur Pee-Laby, in the " Revue Generale de Botanique " 

 for December, 1904, records the curious instance of a plant of 

 the common passion-flower (Passiflora cariiUa) having taken 

 upon it.self a semiparisitic existence. A seed by chance was 

 sown near a plant of Euonymus japoiticus. On germinating 

 apparently normal aerial parts were produced, but below the 

 surface of the soil a union was effected between the passion- 

 flower and the roots of the Eiionymiis, resembling that which 

 takes place between a stock and scion in grafting. A number 

 of roots developed on the passion-flower, so that it was not 

 wholly dependent on the host-plant for its supply of food from 

 the soil. 



CHEMICAL. 



By C. AiNswoRTH MiTCHFLi,, B.A. (Oxon.i, F.I.C. 



The Copper Trea-tment of Wa-ter. 



During the last few months the new method of purifying 

 drinking water by treatment with copper sulphate has been 

 extensively adopted by large waier companies in the United 

 States, where previously some had had to discontinue the use 

 of certain reservoirs owing to the growth of green alga; (" pond 

 scum ") rendering the water absolutely unfit for use. It has 

 been proved that salts of copper possess extraordinary anti- 

 septic powers, far exceeding those of either carbolic acid or 

 formalin, and that the addition of as little as i part of copper 

 sulphate to 5 million or even 50 million parts of the water is suffi- 

 . cient to destroy these low forms of plant life within three or four 

 days. At the same time the growth of higher plants, such as 

 watercress, is not injured, and the treatment is now being suc- 

 cessfully applied to the watercress beds in the Southern States. 

 In Professor Kracmer's opinion this difference in the behaviour 

 of the higher plants and of alga; is due to the fact that the 

 latter are unicellular, so that the entire functions of the 

 organism are simultaneously affected, whereas in higherplants 

 the copper can be distributed among the different cells and 



its toxic action diminished. Bacteria being also unicellular, 

 it is not surprising that they, too, are destroyed by copper, 

 though they off^er greater resistance than the alga. Thus Dr. 

 Moore, of the U.S. Department of .Agriculture, has found that the 

 addition of i part of copper sulphate to 100,000 parts of water 

 destroys the micro-organisms of typhoid and cholera within 

 three or four hours. In one experiment a strip of copper 

 placed in water containing some 4000 typhoid bacilli rendered 

 the water sterile in four hours. .As regards the influence of 

 copper upon the human system, several leading .American 

 medical authorities have recorded their opinion that the traces 

 of the metal in water treated by this method could not possibly 

 be injurious. Copper is normally present in different kinds of 

 food, and is eaten in large quantities in preserved peas, a tin 

 of which contains many hundred times as much copper as is 

 present in the treated water. Their general conclusion is that 

 copper and its salts are much less poisonous than has hitherto 

 been supposed, and that they are not cumulative in their 

 action. 



* * * 



BuffaLlos* Milk. 



The composition of buffalos' milk difl'ers greatly from that 

 of the cow, as has been shown by recent analyses made by 

 Herr Windisch of the milk from three buffalo cows. It con- 

 tained from 18 to 20 per cent, of solid substances, of which 

 /•g to 9'2 per cent, was fat (cream) and 077 to o'S3 per cent, 

 mineral salts. The milk of an average cow contains about 

 izh per cent, of solid matter, of which about 4 per cent, is fat 

 and about o\S per cent, mineral salts. Elephants' milk is still 

 richer than that of the buffalo, for it contains about 30 per 

 cent, of solid matter, including 20 per cent, of cream ; while 

 the richest of any known milk is that of the porpoise, with 60 

 per cent, of solid matter and 46 per cent, of cream. The milk 

 sugar in buffalos' milk amounts to about 4^ per cent., as 

 against about 4 per cent, in cows' milk, 20 per cent, in ele- 

 phants' milk, and only ij per cent, in porpoises' milk. 

 « « • 



Yello\v Arsenic. 



Messrs. Stock and Siebcrt have shown that when arsenic is 

 heated in a tube from which the air has been exhausted, it 

 condenses on the sides in a brilliant yellow coating. Arsenic 

 is best known as a grey substance with a metallic lustre, and 

 the yellow modification is slowly re-converted into this ordi 

 nary form when exposed to sunli,L;lit, and rapidly changed when 

 heated in the air. This is an interesting illustration of what 

 the chemists term "allotropic modifications." Chemically the 

 substances are identical, like blacklead and the diamond : but 

 they differ in physical properties, such as density, hardness, 

 and melting point. 



ORNITHOLOGICAL. 



By W. P. PvcRAi-T, A.L.S., F.Z.S., M.B.O.U., &c. 

 Great Snipe in Shetland. 



The "Annals of Scottish Natural History" for January 

 records the occurrence at Unst of a (ireat Snipe {Callina^o 

 major) which was killed on Sept. 30, 1904, and weighed -j], ozs. 

 The I'^ditor remarks that if this record is authentic then it 

 makes the second record for the Shetlands. The doubt here 

 expressed is begotten by the weight, which he seems to regard 

 as somewhat light for this species, since the Common .Snipe 

 sometimes turns the scale at 7J ozs. Mr. J. E. Harting, how- 

 ever, in his valuable handbook, records the weight of the 

 Solitary or Great Snipe as varying between 7.' and 10', ozs. 

 » ♦ » 



The Bea.k of the Hawfinch. 



It may be of interest to the readers of this column to know 

 that in examining some skulls of the Common Hawfinch a few 

 days since I found two skulls still retaining the beak-sheath. 

 On examining these I was surprised to find in the region of the 

 gape, on the inner side of the lower jaw, two large rounded 

 bosses of the size of peas, and having a finely striated surface. 

 On the roof of the palate immediately above, I found an 



