496 



NATURE 



[March 23, 1905 



vestigations on several Harcourt lo-candle pentane lamps 

 and a number of l-'leniing large bulb standard electric glow 

 lamps, which now form the working standards of candle- 

 power. Intercomparisons have been made by means of 

 glow lamps with the National Standards Bureau of Wash- 

 ington, the Electrical Standardising Laboratories of New 

 York, and the Berlin Reichsanstalt. 



In the general electrical department, Mr. Campbell has 

 devised a method for obtaining for inductance measure- 

 ments alternating currents having very high frequencies 

 and a wave form almost a pure sine-curve. A large amount 

 of new apparatus has been set up for testing purposes, 

 mui'h of it of a novel character. 



The standard current balances and electrostatic voltmeters 

 have been studied, and it has been found that the allega- 

 tion that the Kelvin balance, when used with alternating 

 current, is affected by eddy currents in the metal parts 

 near the coils is without foundation for all ordinary 

 frequencies. 



Researches on the distribution of temperature in field coils 

 of dynamos and motors, and on the behaviour of insulating 

 materials under heat treatment, have been made by Mr. 

 Rayner, and form the subject of a report to the engineering 

 standards committee communicated to the Institution of 

 Electrical Engineers at their last meeting. 



In the department of metallurgy. Dr. Carpenter and Mr. 

 Keeling, during the early part of the year, completed their 

 work on the range of solidification and critical ranges 

 of iron-carbon alloys, and an account of the work was read 

 at the meeting of the Iron and Steel Institute in May last. 

 The value of Dr. Carpenter's work was recognised by his 

 election as Carnegie scholar. On Mr. Reeling's leaving 

 the laboratory, Mr. Longmuir, also a Carnegie scholar, 

 was appointed on the staff, and Dr. Carpenter and he have 

 since been carrying on, in cooperation with Mr. Hadfield of 

 Sheffield, an elaborate systematic research on the properties 

 of the nickel-steels. In all, seventeen different kinds of 

 physical, mechanical, and chemical tests have been per- 

 formed on the different samples used, which contained 

 varying amounts of nickel up to i6 per cent. The results 

 obtained will shortly be submitted to the alloys research 

 committee of the Institution of Mechanical Engineers. 



.'\n investigation on modern high-speed tool steels, such 

 as those shown in use in the engineering department on 

 Friday last, has also been completed by Dr. Carpenter, cool- 

 ing curves and photomicrographs having been obtained 

 showing clearly the various modifications in structure after 

 different heat treatment. 



The optical department is rapidly being organised, and, 

 in addition to lens testing, the work has included the 

 accurate measurement of the angles of prisms and deter- 

 mination of the optical constants of numerous samples of 

 glass. 



In the weights and measures department, the chief work 

 has been the study of the master screw of the new leading- 

 screw lathe, which has been carefully calibrated throughout 

 its entire length. 



The foregoing serves to indicate the substantial progress 

 m;ide by the laboratory, and to prove that though it has 

 only been at work a little more than three years, it has 

 already begun to make its mark on the science and industry 

 of the country, and to justify in a large measure the ex- 

 pectations of its promoters. 



FUNGI^ 



H' 



'AVING pointed out that the attempts to derive the 

 word fungus from funere, or funtis and ago, fuiigor, 

 &c., have been shown to be failures — that it comes from 

 the Greek ffiro-y^os, and is the same word as sponge, the 

 lecturer proceeded to give illustrations of the fungi known 

 to the ancients. These were, of course, all of the larger 

 kinds, since no knowledge of micro-fungi was possible. 

 Nevertheless, references in the Old Testament show that 

 certain diseases — mildew, smuts, &c. — were known to the 

 Hebrews, but of courje their connection with fungi was not 

 suspected. 



1 .\b<>tracl of a discourse delivered at the Royal Institution on February 

 34 by Prof. H. Marshall Ward, F.R.S. 



NO. 1847, ^'OL. 71] 



The Greeks and Romans not only knew several forms of 

 .-\manita, .\garicus, Boletus. Polyporus, and of Truffles, 

 Morels, &c., but they discriminated clearly between the 

 poisonous and wholesome species. 



Their ideas as to the nature and origin of such fungi 

 seem childish to us, but they were consistent with the naif 

 attitude of the Greeks towards natural objects. Theo- 

 phrastus, about 320 B.C., Dioscorides, about 60 B.C., and 

 Pliny, for example, argued that since truffles and other 

 fungi had no roots, leaves, stems, &c., they are objects 

 apart. They arise spontaneously from earth, or by fermenta- 

 tion from the sap of trees, or froin water. 



It is interesting to note that Polyporus officinalis was im- 

 ported and used as an article of medicine not only during 

 classical times, but also for centuries afterwards. 



In mcdireval times the herbalists chiefly copied from 

 Galen, Theophrastus, &c., and as they had no figures the 

 early herbals give us little information. In 1576, however, 

 Clusius gave a series of wood-cuts which are will worth 

 looking at, and in 1601 he made a series of water-colour 

 sketches of eighty-two of the fungi of Austria — the first 

 drawings of the kind known. Figures in Dalechamps, 

 1536, Dodoens, 1583, and Parkinson, 1640, may also be 

 compared. 



The next step forward was only possible after the micro- 

 scope had come into use as a scientific instrument. 



It is a curious point that abundant and conspicuous as 

 the powdery spores of th." fungi are, no one seems to have 

 observed their importance until Micheli, in 1729, collected 

 and sowed a series of them, and with results, for he obtained 

 mycelia, and in a few cases even sporophores ; but it was 

 not until a century later, 1820, that Ehrenberg, in his classical 

 " De Mycetogenesi," traced the larger fungi to their my- 

 celial filaments, collected and sowed spores, and grew several 

 species of Moulds, and especially discovered the sexual act 

 in Zyzygites. For although Micheli 's ideas had been con- 

 firmed by Gleditsch in 1753 and by Schaeffer in 1762, 

 Rudolphi and Persoon had more or less denied the ger- 

 mination of spores, and insisted on the spontaneous genera- 

 tion of the ttioulds. 



However, before 1840 Nees von Esenbeck had cultivated 

 a Mucor from spore to spore, and Dutrochet, 1834, and 

 Trog, 1837, had seen the " puffing " of asci and practically 

 established the doctrine of wind-distribution of spores. 



By these and similar successes the era of the Mould-fungi 

 was initiated, and the labours of Corda, Tulasne, Prings- 

 heim, Cohn, and De Bary soon introduced system into their 

 study, and especially the exact study of life-histories showed 

 what important results for morphology lay in the biological 

 investigations of these micro-fungi. 



The lecturer here gave illustrations of the commoner types 

 of mould fungi, with notes on their botanical importance, 

 and some remarks on the points he wished to emphasise 

 later. 



An early outcome of the investigations of the moulds and 

 their allies was the discovery of what curious substrata some 

 of them grow upon. A rapid survey of all saprophytic 

 fungi shows that while the inajority grow on the soil, on 

 plant remains, or on dung of various kinds, peculiar forms 

 or species occur on such bodies as resin, cork, bees' and 

 wasps' nests, bones, limestone, insect-remains, horn, hair, 

 feathers and hoofs, fats, and in chemical solutions such 

 as picric acid, copper sulphate, arsenic, and poisons such 

 as atropin, muscarin, and so forth. 



Here, also, the lecturer gave sotiie notes on details, of 

 which the most striking was. perhaps, his own proof thai 

 the horn-destroying fungus will not act until its spores have 

 been passed through the alimentary tract of an aniinal, 01 

 subjected to the influence of gastric juice. 



In 1866, the year of publication of De Bary's book on 

 inycology, a revolution in the study of fungi was brought 

 about by the first morphological proof of parasitism and in- 

 fection, and the clear distinction drawn between the sapro- 

 phytic micro-fungi or " iimulds " and the parasitic fungi 

 which induce " disease > " The matter was of especial 

 importance as explaining; away prevalent erroneous ideas 

 according to which thesi- disease-fungi were outgrowths 

 (exanthemata) from the ii:oribund tissues of the host-plant 

 itself. 



De Bary's great service was to prove that a spore of a 

 fungus arrived from outside, and after germinating on the 



I 



