April 2, 1885] 



NA TURE 



521 



devices with the same object in view, consisting of small channels 

 or shafts brought up from the top of the reservoir to the seat of 

 the lamp flame, are adopted in some American lamps, ll these 

 openings or channels were protected, in accordance with the 

 well-known principles which govern the construction of miners' 

 safety lamps, so as to preclude the possibility of flame passing 

 them, they would obviously be unobjectionable, and indeed in 

 one or two instances of modern lamps the openings which have 

 been provided for the escape of expanding air or vapour are of 

 such dimensions that flame could not pass. A simple arrange- 

 ment which would effect the desired object with perfect safety, 

 and would at the same time protect the lamp wicks from 

 deterioration by the grosser impurities sometimes contained in 

 portions of a supply of oil, is to attach to the bottom of the burner 

 a cylinder of wire gauze of the requisite fineness (twenty-eight 

 meshes to the inch) which would contain the wicks, and would 

 allow the passage of air or vapour through it towards the burner, 

 while it would effectually prevent the transmission of fire from 

 the lamp-flame to the air-space of the reservoir. 



Some of the more prominent points elicited by the inquiry in 

 progress, as to the causes of explosions in petroleum lamps, and 

 the conditions which regulate their efficiency and safety, having 

 now been noticed, it remains to offer a fesv simple suggestions, 

 attention to which cannot but serve to reduce the risks of 

 accident which attend the use of petroleum and paraffin oil : — 



1. It is desirable that the reservoir of the lamp should be of 

 metal. U should have no opening or feeding place in the reser- 

 voir, nor should there be any opening or channel of communica- 

 tion to the reservoir at or near the burner, unless protected by 

 fine wire gauze, or packed with wire, or unless it is of a diameter 

 not exceeding o'o<i inch. 



2. The wick used should be of soft texture and loosely plaited ; 

 i! should fill the entire space of the wick-holder, and should not 

 be so broad as to be compressed within the latter ; it should 

 always be thoroughly dried befoie the fire, when required for 

 use. The fresh u ick or wicks should be but little longer than 

 sufficient to reach to the bottom of the reservoir, and should 

 never be immersed to a less depth than about one-third the total 



the reservoir. 



3. The reservoir or lamp should always be almost filled before 

 use. 



4. If it be desired to lower the flame of the lamp for a time, 

 this should be carefully done, so as not to lower it beneath the 

 metal work deeper than is absolutely necessary ; but it should 

 be borne in mind that even then the combustion of the oil will 

 be imperfect, and that vapour of uncon-umed petroleum will 

 escape, and render the lamp very unpleasant in a room. 



5. When the lamp is to be extinguished, and is not provided 

 with an extinguishing arrangement (of which many excellent 

 forms are now applied to lamps) the flame should be lowered 

 until there is only a flicker ; the mouth should then be brought 

 to a level with the top of the chimney, and a sharp puff of breath 

 should be projected across the opening. The lamp should remain 

 on a firm support when it is being extinguished. 



The lecturer hopes that, pending the more thorough treatment 

 1 this subject by Mr. Redwood and himself when these investi- 

 gations are completed, the points dealt with in this discourse 

 which relate to accidents wi:h petroleum lamps may, on the one 

 band, tend to dispel groundless alarm as to the dangerous nature 

 ofpetioleum and paraffin oil as illuminants, and may, on the 

 other hand, serve to convey some useful information respecting 

 the causes which lead to accidents with lamps and the readiness 

 with which they may be avoided. 



DR. KLEIX ON CHOLERA 



AT a recent meeting of the Abernethian Society of St. Bar- 

 tholomew's Hospital, Dr. Klein briefly reviewed the 

 accepted theories as to the aetiology of cholera, and stated the 

 views concerning it which he had been led to adopt since his 

 to India. His address is of importance as embodying the 

 conclusions of the Indian Commission of Inquiry into this 

 Two main theories are held with regard to the cholera 

 :1m one, which is supported by a large section of the Indian 

 ng that cholera is non-infectious and non-com- 

 municable ; the other, which is upheld \-\ European authorities, 

 ; that it is both infectious an I ( immunicable. In support 

 former theory may b ■'■ I the numerous cases of 



sporadic cholera which occur, and the fact that when troops are 

 attacked in a military cantonment and are at once marched out 

 into camp, no new cases occur other than those which are 

 already incubating. Lastly, in many places in India, in spite of 

 all conditions favourable to a spread of cholera by the evacuations, 

 it is rare for any but sporadic cases to occur. In support of its 

 communicability and infectiousness it is unquestionable that 

 when an outbreak of cholera has occurred, it has in most 

 instances been introduced from a district where cholera was rife, 

 as instanced by the late outbreak at Marseilles, which was shown 

 to have been introduced from Egypt. Some have maintained 

 that it may be conveyed by winds ; against this may be adduced 

 the fact that epidemics have occurred in Malta without any 

 occurring at the same time- in Gozo. Now, Gozo is nearer to 

 Egypt than Malta, and yet no epidemic at Malta has ever been 

 preceded by an epidemic at Gozo. The upholders of the theory 

 of infectiveness are divided into two schools — the contagionists, 

 who consider that the disease is directly communicable from the 

 sick to the healthy, and that the virus is contained in the 

 discharges from the alimentary canal ; and the localists, who 

 believe that the evacuations contain a germ which is capable of 

 elaborating the virus under suitable conditions of climate and 

 soil. Against the contagionists' view must be considered 

 especially these facts — that it is very rare for attendants to be 

 attacked early, and that they only succumb at a late period of 

 the epidemic ; and that cholera patients are treated in the general 

 wards of a large hospital in Calcutta, and yet no cases of con- 

 tagion have occurred. Dr. Koch, in studying this disease, 

 found that the lower parts of the small intestine of patients 

 who died from cholera swarmed with peculiar bacilli (comma 

 bacilli), which passed out with the evacuations, and which 

 he considered were capable of manufacturing the cholera 

 virus when introduced into the small intestine of an unhealthy 

 patient. He also believes that this bacillus is destroyed by the 

 acid secretion of the stomach of a healthy person, and, further, 

 that this bacillus is destroyed by drying ; and hence that this 

 disease could not be propagated by soiled linen after this had 

 been dried. The German Commi-sion believes these bacilli to 

 be the cause of the disease. Dr. Klein, by a series of experi- 

 ments, has proved that these comma bacilli are not destroyed by 

 an acid solution of the same strength as that of the gastric juice ; 

 but that, on the contrary, they thrive after having been immersed 

 in such a solution. Further, that though these bacilli, in com- 

 mon with all germs (except spores of bacilli), are destroyed by 

 thorough and scientific drying, still soiled linen never becomes 

 thoroughly dry. Klein thinks that even the location of these 

 bacilli in the lower part of the small intestine should of itself 

 suggest suspicion, inasmuch as bacilli and micrococci in great 

 numbers are contained in it even in health, and the more because 

 this locality is not the exclusive seat of the disease. More con- 

 clusive evidence, however, was collected by him in India. For 

 instance, three of the houses situate in a certain street in Cal- 

 cutta contained in all eight cases of cholera. Leading out of 

 the street was a narrow lane to a large water-tank, around 

 which was built a squalid rookery. The water of this tank 

 was used in the rookery for all purposes, and contained the 

 comma-bacilli. Now, the houses in the street were not supplied 

 with water from the tank, and yet eight cases of cholera occurred 

 in the square, while none were found in the rookery, which was 

 inhabited by about 200 families. The English Cholera Commis- 

 sion has also found a bacillus apparently similar with the cholera- 

 bacillus in the intestines of children and adults suffering from 

 diarrhoea. Dr. Lewis, of Netley, has found the same in the 

 saliva of healthy persons. With regard to the evacuations con- 

 taining the virus, Dr. Klein found that in India many of the public- 

 built wells were contaminated by sewage, and that tl e water, 

 though nominally not used for drinking purposes, for expediency 

 was generally so used, and especially at night time. Again, at 

 Benares a large sewer opens into the Ganges at a spot where the 

 pilgrims and natives perform their religious ablutions, 1!: 

 eluding especially the washing out of the mouth with the river 

 water. In spite of this only sporadic cases of cholera occur. 

 Dr. Klein has been led to the conclusion with regard to the 

 cholera— that Koch's bacillus cannot be the cholera germ. 



SCIENTIFIC SERIALS 

 American Journal of Science, March.— Prof. Marsh's mono- 

 graph on the Dinocerata, by L. P. B. This valuable contribu- 

 tion to American palaeontology forms a sequel to the author's 



