October 22, 1908] 



NA TURE 



645 



It is arranged that an international bureau will be 

 established for the purpose of regulating investigation and 

 proiTioting uniformity in the methods of testing both 

 machinery and products under the action of cold. The 

 necessity of some such bureau was conclusively shown in 

 the discussion on units. Certain people were desirous of 

 introducing other than the C.G.S. units, and of stereo- 

 typing such units as the " frigorie " by a definition other 

 than the present one of a negative calorie. It was felt, 

 however, that these questions were too large for the section 

 to discuss, and impossible for a full congress, so that they 

 were left for the projected commission or bureau. 



A question of prime importance in connection with the 

 congress is that of a knowledge of the properties of the 

 various non-conductors of heat used in practice. Up to the 

 present most of the determinations published have been 

 either on too costly materials or else on common materials 

 in other conditions than those used in practice. The 

 determination of coefficients of conductivity is one of no 

 small difficulty, and an interesting review of various methods 

 was given by Mr. W. D. A. Bost. A large series of 

 careful measurements of the coefficients of conductivity of 

 material in the form of thin plates has been made by 

 M. A. Desvignes, using Lodge's modification of Forbes's 

 method. Since the temperature coefficient for such bad 

 conductors appears to be very small, the error introduced 

 by applying such numbers to temperatures lower than 

 tlie ordinary at which they were determined can only 

 be one or two per cent. Much greater uncertainty is 

 introduced owing to the different plivsical conditions of 

 materials in practice, and also to the length of time before 

 materials of considerable thickness really arrive at a steady 

 state with regard to the flow of heat, and thus come into 

 the condition in which the coefficients determined as above 

 are applicable. From his own measurements Mr. G. 

 N^oorhees stated that as much as six days was necessary, 

 even with thicknesses of the order of a decimetre, before 

 the conductivity was proportional to the thickness. Again, 

 nearly all non-conducting walls are composite, either being 

 built up by bricks or slabs, or in several layers with an 

 air space between, or both combined. The conductivity is 

 thus much more complicated, and it is very questionable 

 whether any satisfactory conclusions could be arrived at 

 without more complete investigation on these various 

 questions. 



On the production of cold there were several interesting 

 papers describing the various methods used and summing 

 up their efficiency. 



New elements were introduced by the description of a 

 novel rotating machine using sulphur dioxide, invented by 

 M. .SingrCin. In this machine the outside of the hermetically 

 closed condenser is kept in continual rotation, the inner 

 parts being hung and kept in place by their weight. Some 

 small machines were in actual work, and certainly produced 

 ice very rapidly and easily with an apparently small con- 

 sumption of power ; but no figures were given or indicators 

 used to show exactly w-hat was happening. There seems 

 no doubt that the principle is new and most useful for 

 small machines, as there is little lubrication and no taps 

 to get out of order. In the case of the usual compressors, 

 considerable economy can be gained by the use of the 

 multiple-effect method. In this case the same cylinder is 

 used for two or more pressures at the samp stroke by a 

 proper system of ports and connections. The result is 

 that the usual indicator diagram, which has a very sharp 

 peak, for such machines, is much broadened there, and 

 the same plant has thus a considerably higher working 

 value. 



The sections devoting themselves to the application of 

 refrigeration to food were concerned with the construction 

 of cold stores of all descriptions, about which there was 

 nothing of general interest. The effect of different degrees 

 of cold and humidity is being studied very carefully by the 

 United States Department of Agriculture, and some of the 

 results were given by Miss E. Pennington. Experiments on 

 chickens varied in length from a few hours to four years, 

 both on chickens bought in the open market and with those 

 the history of which was known. It was found that, as 

 would be expected, the various bacilli were more numerous in 

 th-3 former class, and their numbers appeared to increase up 

 to about a year, and then to decrease. Even at the end 



NO. 2034, VOL. 78] 



of four years there were some living. These long periods 

 are not often employed in practice, about five months being 

 the average at present. Very interesting photomicrographs 

 were exhibited showing the gradual breaking down of 

 the muscles, owing to the intrusion of foreign matter which 

 increased with the time. In some cases the breakage was 

 sharply at right angles to the muscle, which rendered the 

 material very brittle. The material was also examined 

 chemically, the changes which occurred being much greater 

 in the open market class, and all tend to prove that the 

 action is due to enzymes and not to bacteria. The loss of 

 water, though great, was not of any dietetic importance, 

 though it would affect the commercial value, but this might 

 be controlled to a large extent. 



One interesting point was the occurrence of mould at the 

 end of very long terms. There seemed no reason to suppose 

 that the mould had appeared after removal from the cold 

 store, as the time was so short before examination. This 

 is important in connection with the present position of 

 the authorities in England and France with regard to 

 moulds, those on rabbits and meat being assumed to render 

 them unfit for food, while they are allowed on hams, &c. 



Similar investigations en a less elaborate scale, with 

 other food-stuffs and either frozen (-9° C. to —12° C.) 

 or chilled (-1° to -2° C), were given by other investiga- 

 tors. The results point to the necessity of finding the 

 most suitable temperature for each material and of care in 

 thawing, and also of using pure water for this proceeding. 

 Under rnodern conditions and for reasonable times, there 

 seems to be no appreciable decrease in the nutritive effects 

 of food materials due 10 refrigeration ; in fact, many harm- 

 ful parasites are less likely to be present in frozen than 

 in unfrozen meat and other foods. 



In the production of flowers for market it is of great 

 advantage to be able to have them as early as possible. 

 It appears that in many cases the time of flowering can 

 be advanced nearly two months by checking the foliage at 

 a critical time. The investigations are only in their infancy, 

 but promise very important results. 



The use of dry air is of importance in many industries 

 at the present t'ime, and the employment of considerable 

 cold appears to be the most convenient and economical 

 means of obtaining it. This is markedly the case in 

 the production of pig-iron in the blast-furnace, where the 

 usual amount of humidity in the air leads to a considerable 

 loss. It is said that by reducing the humidity to 6 grains 

 per cubic foot, an increase of output of 26 4 per cent, and a 

 saving of fuel of 13-4 per cent, has been obtained. 



In "the section devoted to le,gislation it became clear how 

 extremely important it now is to have united effort in 

 refrigeration matters, and its great importance to the 

 British Empire was emphasised. In view of this im- 

 portance it is remarkable, and entirely characteristic, that 

 the British Government, in marked distinction to other 

 countries, paid no attention to the congress. 



In addition to the sectional meetings, congress lectures 

 were given by Profs, von Linde and d'Arsonval. The 

 former enlarged on the use of cold in dwelling houses, 

 and took as his text the saying that the use of cold 

 would advance civilisation in the tropics in a manner 

 similar to that in which the teinperate regions had been 

 advanced by the employment of means of heating. Prof. 

 d'Arsonval 'lectured on' the science and industry of cold, 

 reviewing our present position, and in this way closed a 

 successful congress, in which nearly 4000 people, drawn 

 from the whole world, took part. 



It was decided to hold the next congress at Vienna m 

 igio, after which they will be triennial. 



LOCAL ASSOCIATIONS FOR PROMOTING 

 EUGENICS.' 

 T PROPOSE to take the present opportunity of sub- 

 ■'■ mitting some views of my own relating to that large 

 province of eugenics which is concerned with favour- 

 ing the families of those who are exceptionally fit for 

 citizenship. Consequently, little or nothing will be said 

 relating to what has been well termed by_ Dr. Saleeby 

 " negative " eugenics, namely, with hindering the 



1 Adilress to a meeting of the Eueenic^ Education Society at the Grafton 

 Galleries, on October 14. by Francis Galton, F.R.S. 



