August 17, 1893] 



NA TURE 



175 



338^~ + 27~ to 3-|.7'+i9iS its radiant being very probably 

 at 2i\'-\-\Z' near the head of Draco. 



On August 14 the atmosphere was unusually clear, and 

 during the four hours from about loh. 15m. to I4h. 15m. 

 I observed fifty-six meteors. The Perseid shower was 

 still distinctly visible, and the meteors pretty bright. From 

 seven accurately observed paths a very good radiant was 

 obtained at 49' + 57'. There was also a well-defined 

 shower of streak-leaving meteors from Camelopardus at 

 61° -|- 59", and these, if confused with the Perseids, would 

 have given the litter radiant a very diffused appearance. 

 On this and the preceding nights I saw many C> gnids and 

 Cepheids from radiants at 292' + 53° (sixteen meteors) 

 and 3ir-)-62 (fourteen meteors), and this pair of 

 showers formed by far the most important of the minor 

 displays of the epoch. I had in previous years detected 

 the Cygnids, but never remember to have seen the 

 shower of Cepheids on such activity. 



On comparison of my Perseid radiants deduced, on 

 August 5, 8, 9, 10, 12, 1 3 and 14 it will be seen that they ex- 

 hibit an easterly movement in satisfactory agreement with 

 my observations in preceding years. This remarkable 

 displacement of the radiant may now almost be regarded 

 as "an old story " but it will always remain a very sig- 

 nificant and interesting feature of the shower both from 

 an observational and theoretical standpoint. The motion 

 of the radiant amongst the stars may be nearly as easily 

 and certainly observed by an experienced and precise 

 observer as the motion of a comet. The circumstances 

 are different of course, for a radiant is simply an apparent 

 position and not a visible object, but trustworthy obser- 

 vations define this position with considerable exactness, 

 though it is impossible to eliminate all the sources of error. 



Mr. Corder, at Bridgwater, informs me that on August 

 10, be'ore i4h. he counted 129 meteors, but he regarded 

 the display as rather a poor one. The mean position of 

 the radiant was at \\'-\-^']W but he considers that it shifted 

 from 4o^+56J° to 47^-|-58l° during his observation. 



Mr. Corder, watching until Ijh. on August 13, counted 

 77 meteors, but he says the Perseids had almost ceased, 

 and gave an uncertain radiant, but such as it was could 

 be located near the stars B and C Camelopardi. He 

 found a very active and well-defined shower of Cygnids 

 from the point 293° -)- 50°. W. F. Denning. 



CHOLERA AND ARTICLES OF DIET. 



A LTHOUGH in by far the larger number of cases 

 -^*- the distribution of cholera has been traced to the 

 use of impure water, yet there are a few authentic instances 

 on record of its dissemination by means of various 

 articles of diet, such as milk, fruit, salad, whilst Kossel 

 and Steyerthal quite recently report two cases {Deutsche 

 meii. IVocheiischrift, 1 892) in which its communication was 

 traced to bread and butler. It becomes, therefore, not 

 only of interest but importance, to ascertain what is the 

 vitality of the cholera organism when purposely brought 

 in contact either superficially or incorporated with various 

 articles of food. Researches in this direction have been 

 undertaken from time to time by various investigators, 

 Babes, Celli and others, whilst Dunham's experiments 

 published in the Mediinl Record iox 1892 are amongst 

 the most recent and exhaustive on this subject. This 

 author found that cholera organisms purposely intro- 

 duced on to salad leaves and placed in a covered dish 

 and kept at the ordinary temperature of a room, retained 

 their vitality for five days, on cooked cauliflowers for 

 : from six to ten days, and on the same vegetable uncooked 

 I for thirteen days. On a sliced sir iwberry they did not 

 j survive more than twenty-four hours. 



Some important contributions to our knowledge of this 

 subject have been made by Friedrich, and arc brought 

 together in an elaborate memoir, " Beitrage zum Verhal- 



NO. 1242. VOL. 48] 



ten der Cholerabakterien auf Nahrungs und Genu.'s- 

 mitteln " published in the Arbeiten a. d. Kaiserlichen 

 Gesiindheitsamie, vol. viii. 1893, p. 465. 



The range of materials investigated is very extensive, 

 upwards of fifty different articles being specially studied 

 in this respect, including numerous kinds of fruit, several 

 vegetables, besides milk, tea, coffee and cocoa, also 

 particular descriptions of beer and wine, whilst amongst 

 the miscellaneous materials examined may be mentioned 

 caviar, biscuits, bonbons, tobacco, and snuff! 



In the majority of cases the bacilli were not only 

 rubbed on to the surface of the various fruits and vege- 

 tables, but were also inoculated on to slices, so that the 

 effect on the bacillus of the composition of a particular 

 fruit or vegetable could be ascertained. When simply 

 exposed on the exterior of a given material, ihe vitality 

 of the bacillus depends chiefly on the degree of moisture 

 which is present in its environment, this organism being 

 specially characterised by its rapid destruction in dry 

 surroundings, but when brought in contact with the juices 

 it is the proportion of fruit acid and sugar present which 

 primarily determine its behaviour. The cholera bacilli 

 are very sensitive to acid, and hence their destruction 

 on most slices of fruit in from one to six hours. 



Thus when inoculated on to slices of bright red xery 

 juicy and sour cherries, the bacilli were annihilated in 

 three hours, whilst when simply rubbed on the surface 

 and kept in a moist atmosphere they were still alive at 

 the end of five days. On the other hand, when thus treated 

 and exposed to the ordinary air of a room, the bacilli 

 could not be found after twenty-four hours, whdst when 

 placed in the direct sunshine their vitality was limited to 

 one hour and a half 



But even on slices of fruit containing a much smaller 

 amount of acid, such as pears, the vitality of the cholera 

 organism was not much prolonged, and the reason for this 

 must be sought in the fact that, when grown in solutions 

 contain ng sugar, this organism produces acid, and the 

 acid thus produced impedes its further development and 

 destroys its vitality. 



On vegetables such as cucumbers, cauliflowers, 

 cabbages, the cholera bacillus maintains its existence 

 for several days ; thus on spinach leaves preserved in a 

 damp atmosphere, the bacilli were still present after 

 twelve days, and even when exposed to the ordinary air 

 of a room they did not disappear until after six days. 



As regards the behaviour of the cholera organisms in 

 tea it is interesting to note that in a 3 per cent, infusion 

 of black Chinese tea they are destroyed within twenty- 

 four hours, whilst in a 4 per cent, infusion no trace of 

 them could be found at the end of sixty minutes. 



Friedrich has confirmed the results of other investi- 

 gators on the bactericidal properties of coffee, finding 

 two hours' immersion in a 6 per cent, infusion of this 

 material sufficient for the de truction of these organisms. 

 In various kinds of beer, Munich, Pilsener, and Lager, 

 they could not survive more than from one to three 

 hours, but still more rapid was their extinction in white 

 and red wine, for five minutes after their introduction 

 they could no longer be found in the former, whilst in the 

 latter their vitality did not exceed twenty minutes. 



From the numerous investigations recorded it is 

 obvious that during any epidemic of cholera the con- 

 sumption of uncooked fruit and vegetables should be 

 avoided, or that at any rate precautions should be taken 

 to ensure their sterility by careful cleansing or by the 

 removal of the rind or skin where possible. 



G. C. Franki.and. 



NOTES. 

 Mev of scieice throaghoat the world will be g'ad to know 

 that the honour of knighthood has been conferred upon Dr. 

 Joseph Henry Gilbert, F.R.S., who has been associa'ed for 



