Grace Frankland - Bacteria in Daily Life

Portions of cigar-stumps smoked by phthisical persons in whose saliva the tubercle bacillus was known to be abundantly present were inoculated into guinea-pigs, with the result that fifty per cent. of the animals thus treated succumbed to tuberculosis. Thus neither the fumes nor juice of the tobacco had destroyed the consumption bacillus. In these experiments the cigar ends were used directly they were discarded, in another series of investigations they were collected and kept in a dry place for from fifteen to twenty days before being tested; but even storage for this length of time did not prevent the animals inoculated with them from contracting tuberculosis. In another series of experiments Dr. Peserico kept the infected cigar-ends in damp surroundings, and it was satisfactory to find that under these conditions the tubercle bacillus at the end of ten days was entirely deprived of its virulence. Encouraged by these results, inoculations were made with cigar-ends which had been left in the open and exposed to normal atmospheric conditions, which included falls of rain and snow, and in this case also no symptoms of tuberculosis followed their introduction into the guinea-pigs. These experiments show that the tubercle bacillus is prejudicially affected by contact with tobacco when the latter is kept in a moist condition, but that in a dry condition the properties in tobacco inimical to its vitality are not liberated and the bacillus can retain its virulent properties for a period of over twenty days.

In view of the importance of this discovery on the destruction of the toxic character of the tubercle bacillus by contact with moist tobacco, further experiments were made in which emulsions of tobacco were infected with tuberculous sputum. It was found that the bacilli steadily declined in virulence as the length of time they were kept in the emulsion was prolonged. Thus whereas after a few hours they were still armed with all their virulent properties, after three days, out of the four animals inoculated with the emulsion three succumbed to tuberculosis, after five days two out of four succumbed, whilst after eight days only one animal out of the four was infected, and after a period of ten days' immersion in the tobacco emulsion the tubercle bacillus failed to kill a single animal.

Cigar- and cigarette-ends were collected from the streets and cafés of Padua by Peserico, but in spite of consumption being stated to be very prevalent in this city, in no single case could the presence of the tubercle bacillus be discovered, although, as in the other investigations, the surest method for its detection, i. e. animal inoculations, was employed.

Brief reference may be made also to the experiments conducted to ascertain if cigars and cigarettes, as sold, contain the tubercle bacillus. The more interest attaches to this investigation because it is well known that the operators employed in tobacco factories are, as a rule, an unhealthy class, diseases of the respiratory organs, and especially tuberculosis, being very prevalent amongst them. A German official report on this subject states that the average duration of life of such factory hands only reaches thirty-eight years. Doubtless the lightness of the occupation encourages many to seek employment in these factories whose state of health would debar them from obtaining work under more trying circumstances. Some of the conditions under which cigars and cigarettes are made, such as the workers using their saliva to facilitate the rolling of them and fixing of the leaves, and the testing of the "drawing" properties of a cigar by placing it in the mouth, with the facilities offered for the dissemination of dried tuberculous sputum as dust, contribute to make it highly probable that tobacco as it leaves the factory may contain the germs of consumption.

Before leaving the subject of tobacco and disease germs it may be of interest to inquire what justification in fact there is for the practice adopted by anxious mothers, when travelling in times of epidemics of zymotic disease, of thrusting themselves and their children into the sanctum of the other sex – the smoking compartment of a railway carriage. I have frequently seen this done, despite the voluble protests of its legitimate occupants. Tassinari has made some very interesting experiments on the effect of tobacco smoke on the vitality of various descriptions of disease germs. He constructed an apparatus in which he suspended pieces of linen soaked in broth infected with the particular micro-organism to be tested. Tobacco smoke was then admitted, and the microbes were retained in this stifling atmosphere for half an hour. In these surroundings cholera and typhoid germs were destroyed, and other bacteria, such as the anthrax bacillus and the pneumonia bacillus, were so prejudicially affected, that when subsequently transferred to their normal surroundings it was only with extreme difficulty that they could be revived. When, however, the tobacco smoke was made to pass through water before reaching the bacteria, its pernicious influence was entirely removed, and the latter suffered no detriment. Hence the practice, so often seen in the East, of passing tobacco smoke through rose or other perfumed water before inhaling it, whilst doubtless rendering it less noxious to the smoker, deprives the exhaled tobacco fumes of all their bactericidal or disinfecting properties.

To return, however, after this somewhat lengthy digression, to the question of dust and its bacterial properties, we have learnt enough to enable us to realise that the movement for the migration of the working-classes from crowded streets to rural districts, in which Mr. George Cadbury has played so practical and important a part in the creation of his model village, with its gardens and open spaces, some five miles from the city of Birmingham, is, if only bacterially considered, a very real barrier against the dissemination of disease, for the denser the population, the greater will be the crowd of bacteria, and the greater the chance of pathogenic varieties being present amongst them. Again, we know that sunshine is one of the most potent germicides with which nature has provided us; 2 2 See "Sunshine and Life." and it requires no effort of the imagination to realise how, in the gloomy back courts and crowded tenements of our great smoke-laden cities, bacteria succeed in obtaining a firm hold on their surroundings, and, in the shape of spores, attaining an undesirable and hoary old age, in which they are in some cases almost indestructible. Fräulein Dr. E. Concornotti has shown that this is no figment of fancy only, for she has recently made a special and very elaborate study of the distribution of pathogenic or disease bacteria in air, searching for them in the most varied surroundings, such as prisons, schools, casual wards, etc., with the result that, out of forty-six experiments in which the character of the bacteria found was tested by inoculation into animals, thirty-two yielded organisms which were pathogenic. Dr. Concornotti concludes her valuable memoir by stating that her investigations proved conclusively that the dirtier or more slumlike the surroundings, the greater was the frequency with which she found bacteria associated with disease in the air.

Messrs. Valenti and Terrari-Lelli have quite recently been able fully to endorse these statements in the results they have obtained in their systematic study of the bacterial contents of the air in the city of Modena. In their report they state that the narrower and more crowded the streets, the greater was the number of bacteria present in the air, and the more frequently did they meet with varieties associated with septic disease.

Numerous detailed investigations have also been made of the bacterial contents of the dust in hospitals. That cases of infection arising within hospital precincts are of no uncommon occurrence may be gathered from the observations made by Lutand and Hogg, who report no fewer than 2,294 such cases having arisen in the space of six years in certain Paris hospitals, whilst Solowjew records 1,880 cases as occurring in the space of four and a half months in the St. Petersburg city hospital. Solowjew made a special study of the bacterial contents of dust collected in hospitals, and states that 41·8 per cent. of the samples examined contained disease germs. The degree of infection possessed by dust in such surroundings must, of course, depend upon the degree of cleanliness which characterises the management of any particular institution; and such investigations as the above can only help to emphasise the immense importance of common cleanliness and the reasonableness of taking every precaution possible in the disinfection of utensils, etc.