March 17, 1898] 



NATURE 



469 



scriptions in support of this scheme for perpetuating Dr. 

 Haughton's memory may be sent to Prof. D. J. Cunningham, 

 Hon. Secretary, Royal Zoological Society, Dublin. 



The death is announced of Prof. Kirk, Fellow of the Linnean 

 Society. Prof. Kirk (says the Times), who was of Scotch ex- 

 traction, spent the greater part of a long life in the Colony of 

 New Zealand. In connection with the Department of Woods 

 and Forests he rendered valuable official service. He was a 

 distinguished botanist, and his " Forest Flora of New Zealand " 

 is the standard work upon the forest growths native to the 

 islands. Since the production of his principal work he has con- 

 tinued, from time to time, to publish interesting monographs 

 upon New Zealand timbers. A very valuable report on the trees 

 suitable for forest cultivation in the Colony was issued by him in 

 1886, at which time he held the position of Conservator of State 

 Forests in New Zealand ; and he is understood to have been 

 engaged up to the moment of his death upon a great work de- 

 voted to the botany of Australasia. Prof. Kirk was an eminent 

 member of the New Zealand Institute, and his loss will be 

 much deplored in scientific circles, both in England and 

 Australasia. 



We regret to announce that Dr. Ferdinand Hurter, who had 

 been in weak health for some time past, died suddenly at his 

 residence near Liverpool last Saturday. Dr. Hurter was a native 

 of Schaffhausen, in Switzerland, where he was born in 1844. 

 He early turned his attention to chemistry and its practical 

 applications, and after serving an apprenticeship to a dyer in 

 Winterhun, he pursued the same science at Zurich Polytechnic, 

 whence he proceeded to Heidelberg, where he took his Doctor's 

 degree in 1866. In the following year he came to reside in 

 England, and was appointed consulting chemist to Messrs. 

 Gaskell and Deacon at Widnes. On the formation of the 

 United Alkali Company, he occupied the same position of 

 principal chemist to that firm. In addition to much work con- 

 nected with his own profession, he will also be remembered for 

 his investigations of photometric subjects, and particularly for a 

 very thorough inquiry, which he made some years back in co- 

 operation with Mr. Driffield, into the action of light on :the 

 photographic film. Some of the scientific results to which he 

 was led in the cause of the inquiry have been questioned ; but 

 his work had great effect in improving the artistic character of 

 photographic reproduction, by his discussion of the effects of 

 varying the exposure, and his insistence on the truthful rendering 

 of tone. Dr. Hurter was prominently connected with the local 

 scientific societies, having occupied the position of President of 

 both the Chemical and Physical Societies of Liverpool. 



The first number of the new volume of the Rendiconti del 

 Reale Istituto Lombardo contains the conditions and particulars 

 of the prizes offered for competition in 1898 and 1899. Most of 

 these prizes are open to all nations ; but the essays must be 

 written in Italian, French, or Latin, and forwarded under a 

 motto to the Secretary of the Istituto Lombardo, Palazzo di 

 Brera, Milan. The prizes of general interest are the following : 

 (i) The Institute's prize of 1200 lire for the most complete 

 catalogue of extraordinary meteorological events from the most 

 ancient times down to 1800, excluding auroras and earthquakes, 

 which have already been catalogued. Last date. May i, 1899. 

 (2) The Cagnola prize of 2500 lire and a gold medal (value 

 500 lire) for a critical review of the theory of electric dissociation, 

 with new experiments. Last date, April 30, 1898. (3) The 

 Brambilla prize of 4000 lire to whoever shall have introduced 

 into Lombardy the most useful new machinery or industrial pro- 

 cess. Names to be sent in by April 30, 1898. (4) The Secco- 

 Comneno prize of 864 lire for the best description of the Italian 

 phosphate beds, and proposals concerning their exploitation. 



NO. 1 48 1, VOL. 57] 



Last date, April 30, 1902. All essays must be accompanied by 

 an envelope bearing the motto outside, and the name and address 

 of the competitor inside. 



A VERY valuable volume on the sanitary circumstances and 

 administration of 220 urban districts of England and Wales has 

 been issued as a supplement to the report of the medical officer 

 in the twenty-fourth annual report of the Local Government 

 Board (1894-95). The volume summarises the results of the 

 general sanitary survey of urban districts organised by the late 

 Dr. F. W. Barry, and carried out under his supervision during 

 the period 1893-95. It contains the results of one of the most 

 important pieces of administrative work ever undertaken by the 

 Medical Department of the Local Government Board, and as a 

 trustworthy statement of the sanitary conditions of urban dis- 

 tricts is invaluable. The districts are arranged in alphabetical 

 order, and under each is described the conditions of dwellings 

 and their surroundings, water supply, sewerage and drainage, 

 methods of excrement and refuse disposal and removal, and con- 

 ditions and nature of supervision over registered premises and 

 trades. The general character and efficiency of the administra- 

 tion of the sanitary authority of each district is described under 

 a separate heading. . The present report, with the one previously 

 published on port and riparial districts, contains the results of 

 the sanitary survey of 396 districts, the topographical positions 

 of which are shown upon a map. It is to be regretted that a . 

 survey of such distinct value to public health could not be 

 made to embrace the whole of England and Wales. 



A PRACTICAL demonstration of Dr. Carl Linde's method of 

 producing extreme cold and liquefying air was given in the 

 rooms of the Society of Arts on Monday and Tuesday ; and the 

 apparatus employed is described by Prof. J- A. Ewing in the 

 current number of the Society's Journal (March 11). The 

 method, it may be remembered, is a regenerative one ; that is 

 to say, the cold produced by the treatment of one portion of 

 air is communicated to the portion which is next coming 

 on to be treated, with the result that the air undergoes con- 

 tinuous cooling, which is only limited by the leakage of heat 

 into the apparatus from outside. In Dr. Linde's apparatus the 

 step-down or drop in temperature is produced by letting com- 

 pressed air escape through a small orifice from a region of high 

 pressure to one of low pressure. As air is not a perfect gas, 

 in the thermodynamic sense, it is slightly cooled by the ex- 

 pansion it undergoes, even though it does no work. The fall 

 of temperature is little more than a quarter of a degree for each 

 atmosphere of difference in pressure between the two sides of 

 the orifice ; but Dr. Linde has shown that this small amount 

 is enough to furnish the step-down necessary in a regenerative 

 process. The gas, cooled slightly by passing through the 

 orifice, gives up its cold to gas which is approaching the orifice. 

 The passage through the orifice cools that gas further, and so 

 on, with the result that a cumulative cooling proceeds. A 

 temperature of - 200° C, or lower, may thus be obtained 

 without much difficulty. The machine exhibited at the Society 

 of Arts circulated about 15 cubic metres per hour in a circuit 

 in which the fall of pressure was from 200 atmospheres to 16 

 atmospheres. About 09 litres of liquid air was produced per 

 hour, with a continuous expenditure of three horse-power. Dr. 

 Linde is constructing a machine of 120 horse-power for the 

 Rhenania Chemical Works at Aix-la-Chapelle, which is to be 

 applied to the improvement of the Deacon process of chlorine 

 manufacture. This machine is expected to produce 50 litres 

 of liquid air per hour. 



Attention has recently been called, in two communications, 

 to sources of error likely to arise in temperature determinations 

 by means of thermometer readings. One of these has reference 

 to the possibility of minute errors arising from expansion of the 



