JOHN TYNDALL AND HIS CONTRIBUTION TO THE THEORY OF SPONTANEOUS GENERATION By LYLE A. WEED, Ph .D., M.D. INDIANAPOLIS HE name of Tyndall is well seven to have a formal education and known in the fields of mathe- proceeded to Marburg, Germany, matics, physics and chemistry, where “he graduated in 1850 in the but not so well known in the Philosophical Faculty, taking mathe- fields of biology and medicine. maticsThe as principal subject in viva voce Tonly reference made to Tyndall by most examinations and chemistry and phys- textbooks of bacteriology is to his so- ics’’1 for the two subsidiary subjects. called “Tyndall cone’’ obtained by Thus even with a late start he made a viewing the dispersion of light from the place for himself in educational circles, surfaces of dust particles suspended in and his stay in Germany at this time air. It is not proposed in this article must have brought him in contact with to establish Tyndall as having priority such men as Wohler, Liebig, and prob- in disproving the theory of spontane- ably Pasteur, who were investigating ous generation; but only to show that ferments and the separation of the or- his experiments, which were conclu- ganic from the inorganic. His determi- sive, came at the opportune time to nation to achieve a place in the help swing the balance of opinion in educational world, which so often char- favor of the interpretations accepted acterizes certain types of individuals today, and to review some of his experi- even today; his mental alertness; and ments in bacteriology, which were thor- finally, his contacts with the great men ough, basic, and laid the foundation for of his day, were factors which destined modern bacteriology. him to become a prominent figure in It is not uncommon for a man work- the scientific world. ing in pure science to make funda- While Pasteur, as early as i860, had mental contributions to general biol- performed experiments which he be- ogy, and, indeed, those made by Tyndall lieved disproved the theory of sponta- were made because he was primarily a neous generation, his results were not mathematician, physicist, and chemist. accepted by the rest of the scientific He had very little early formal educa- world, and such men as Needham and tion. His earlier days were spent in the Bastian—who had considerable influ- Highlands of Scotland, out in the coun- ence and a tremendous following—still try away from the crowded districts. He insisted that bacteria did not originate eventually became employed by a rail- from formed masses. The belief was road firm, to do surveying, an occupa- prevalent even in the medical world tion which he found interesting. In that bacteria had little to do with fer- spite of his lack of knowledge of Latin, mentation, putrefaction, and infection he determined at the age of twenty- as the following citations show: The president’s [Huxley’s] discourse, he was beginning to feel the end was . was a popular account of the mode near for in the same address he made a of development and form of those minute bid for closing the issue without further structures which the microscope reveals discussion or investigation when he in such prodigious numbers in infusions added: containing organic matter. He ad- duced arguments in favor of the theory If as Professor Tyndall believes, and as that these various bodies are not distinct his experiments seem to show, bacteria organisms, but are different modes of de- and their germs are killed by boiling them velopment of the same substance. for five minutes, nothing remains but for Next morning, Dr. Bastian gave an ac- us to shake hands over the establishment count of his experiments on the contents of the occurrence of “spontaneous genera- of hermetically sealed cases of preserved tion” and the overthrow of the Germ meats, and he reiterated his conclusion Theory of Disease. that the facts he had just elicited were such as to throw on the Biogenists the burden But Tyndall was not a man to give of proof that life did not really, as was up easily and he began to search for a apparently the case, originate de-nouo way to explain why in certain of his ex- from lifeless materials. A somewhat sharp periments boiling for five minutes did passage of arms took place between Dr. not prevent the development of putre- Bastian and Professor Tyndall, each main- faction. Consequently, in the following taining his well-known view point respect- year he reported to the Royal Society ing the atmospheric germ-theory.15 of London a method for preventing the It is more than interesting that at this growth of organisms in infusions by date (1870) men like Huxley were still using temperatures much below the so much in doubt about the origin of boiling point. In a letter to Huxley, species, and no doubt the attitude of then Secretary of the Society, he wrote: such a great thinker and leader had It is known that the prolonged applica- much to do with the rejection of the tion of a low temperature is often equiva- germ theory of disease. In 1876, Bastian lent to the brief application of a higher stated: one; and you may therefore be disposed to conclude that in the experiments here I have set down the names in order of referred to I have substituted time for in- time, and included my own amongst them tensity. This, however, is not the case. The because those mentioned after me have all result depends solely on the manner in confirmed my results with regard to the which the heat is applied. For example, I putrefaction of some fluids in hermetically boil an infusion for fifteen minutes, ex- sealed vessels, from which the air had been pose it to a temperature of 90° Fahrenheit expelled by boiling; the very experiments, and find it twenty-four hours afterward in fact, which Professor Tyndall (like one waking from a three years’ sleep) now en- swarming with life. I submit a second sam- deavors to impeach by his own one hun- ple of the second infusion to a tempera- dred and thirty-nine failures.18 ture lower than that of boiling water for five minutes, and it is rendered perma- Such caustic comment made before the nently barren. British Medical Society six years after- The secret of the success here is an open ward shows that the struggle to demon- one. I have already referred to the period strate the truth of the germ theory had of latency which precedes the clouding of not made much progress as far as Dr. infusions with visible bacteria. During Bastian was concerned, but it is evident this time the germs are being prepared for their emergence into the finished or- against the proponents of the germ the- ganism. They reach the end of this prep- ory: aration successively—the period of latency of any germ depending on its condition as The author first referred to what is regards dryness and induration. This then, known regarding contagion, and then pro- is my mode of proceeding: Before the ceeded to show that the view, which gave latent period of any one germ is com- the best explanation of the co-existent pleted (say in a few hours after the prep- facts is that which regards it as consisting aration of the infusion), I subject it for of minute living organisms, probably of a brief interval to a temperature which albuminous composition, possessing the may be under that of boiling water. Such power of organic development, always re- softened and vivified germs as are on the producing their own kind; capable, under point of passing into active life are favorable circumstances, of preserving thereby killed; others not yet softened re- their vitality for a considerable period; main intact. I repeat this process well but speedily perishing when separated within the interval necessary for the most from these conditions and freely exposed advanced of those others to finish their to the atmosphere. Dr. Carpenter pointed period of latency. The number of unde- out that ... as to contagion he thought stroyed germs is further diminished by it was to be traced to some organic germ, this second heating. After a number of which might, under certain meteorological repetitions which varies with the character or physical conditions, develop into one of the germs, the infusion, however ob- or another of the diseases to which the stinate, is completely sterilized.5 human body was liable. Mr. J. A. Wank- lyn pointed out that . , as to the nature This process of intermittent heating is of contagion, while not defending the a basic principle applied extensively in chemical theory, he held that, unless they bacteriology and is sometimes today re- could discriminate germs, the germ- ferred to as Tyndallization. theory had no vitality in it. Dr. Mac- In addition to the large amount of Namara was doubtful as to diseases being work that was being done directly on alone capable of reproducing themselves the problem of spontaneous generation, for Scarlet Fever was never found in India, or Cholera in Australia, although both a number of investigators wTere ap- countries were in communication with the proaching the problem indirectly by West and with each other. trying to discover the real nature of the cowpox virus which Jenner had shown In addition to the general comments to be effective in preventing smallpox. made by various investigators and by In an attempt to arrive at the funda- those who did most of their work as mental nature of the substance, Braid- arm-chair philosophers, there were wood and Vacher,12,24 and Maclagan13 many who experimented and reasoned performed a number of experiments at great length to show why the Germ and tried to compare the type of reac- Theory could not be accepted.