IVAN PETROVITCH PAVLOV

564

SPECIAL ARTICLES IVAN PETROVITCH PAVLOV DURING the last twelve months of Pavlov’s life more people who were interested in his work had the privilege of seeing him and hearing him speak than in any other year. The summer of 1935 is memorable both because of his visit to this country for the International Neurological Congress and because of the holding in Russia of the International Physiological Congress. The name of the great physiologist dominated these gatherings, which were attended by representatives from all over the world, and their chief interest to many lay in the opportunity to "see Pavlov." Those who met him on these occasions must count themselves fortunate, for he died in Leningrad on Feb. 27th, at the age of 86. Pavlov was born in September, 1849, in the small city of Riazan in Russia. His family were poor, but his father was a country priest and the foundations of his education were laid in the church school from which he passed to the theological seminary. It seems that this differed from other schools in that the boys were

probably

encouraged to develop their natural inclinations instead of being forced up to the same standard in all subjects. Pavlov became interested in the natural sciences, and at the age of 21 entered what was then St. Petersburg University, and studied Mendeleef under and other eminent teachers. Later, in the Medico-Chirurgical Academy, he came in contact with von Cyon whose stimulating personality had much to do with determining his future career; and after graduation in 1879 he continued research work in the Military Medical Academy under the physician Botkin, obtaining the degree of M.D. in 1883 for a thesis on the nerves to the heart. In 1884 came the opportunity to go abroad, and when he returned to his former position two years later his experience had been enriched by work done in the laboratories of Ludwig and Heidenhain. Thereafter followed his classical contributions to the physiology of digestion, and by 1897, when he published a monograph on the subject, his reputation was international. Meanwhile, at the age of 41, he had been appointed professor of pharmacology in the Medical Academy, and then to the chair of physiology in the new Institute of Experimental Medicine, built by Prince Alexander of Oldenburg. In 1897 he obtained the chair of physiology in the Medico-Chirurgical Academy, relinquishing his professorship of pharmacology, but he still retained his other two posts when. in 1907, he was appointed one of the four scientific members of the St. Petersburg

efferent

of Sciences, and therefore had charge of three laboratories. Most of his personal research was done in the Institute, now known as the AllUnion Institute of Experimental Medicine, of which he was latterly honorary director, as well as director of physiological laboratories in the Russian Academy of Sciences. Although Pavlov emerged after the revolution in more or less the same posts as he had held previously, he suffered more than a change of titles during that difficult time. "Like other scientists he suffered much ... having to carry on his experiments without heat or light, and drawing his main food supply from a little patch of potatoes which he tended himself. But his only complaint was that, with other members of the Academy of Sciences, he had to take his turn in guarding firewood stacked outside the Academy for six hours at a stretch."1

Academy

Pavlov, however, was no stranger to hardship and enabled to survive this period of drudgery and want which must have recalled his earlier struggles. Until he obtained his first professorial post his life had been a continual battle with poverty and difficulties which to a lesser man would have been insurmountable. The animals he used for his researches into the circulation and for his earlier was

experiments

on

digestion

tended by himself and his wife in their own home, and comfort was sacrificed to the thoroughness upon which he insisted in every branch of his work. During his were

SCUUIH1

puuivu

01

uuvui-

secret of his disapproval of the and its principles, but he was treated with tolerance and later received at the hands of Lenin every encouragement and opportunity to pursue his important work. It would be ungenerous to analyse the motives for this policy, which was never varied up to the time of Pavlov’s death. Last year, on his 85th birthday, he was given a pension of 20,000 roubles, and a million roubles for his laboratories. He had but little interest in politics as such, and it is said rarely read a newspaper. He criticised the government in so far as they made academic appointments on political grounds, and more fundamentally because he believed the philo-

sity he made no prevailing regime

sophy they adopted

to rest

on

a

faulty biological to the Physio-

basis ; nevertheless, in his welcome

logical Congress last year he fully identified himself policy of his country. Long after these details of Pavlov’s eventful career have been forgotten his contributions to medical science will perpetuate his name. In the space of ten years he reduced the unexplored field of digestive secretion to an orderly pattern of reflexes,

with the

1 The Times, Feb. 28th, 1936.

565 and definitely established the value of applying to physiology the methods of aseptic surgery. His fistuhe were carefully made, and the scrupulous aftercare of the animals enabled him to keep them alive until they were, to all intents and purposes, restored to normality. The influence of experimental condi-

tions upon his observations was reduced to a minimum. The importance of his famous operation for separating off a pouch from the stomach, in which the gastric secretion could be studied uncontaminated with food, rested upon the " normality" of the pouch. Its nerve- and blood-supply were left intact, and no detail was overlooked which would serve to make it in all respects a faithful miniature of the stomach itself. Pavlov never made the mistake of forgetting that the organ he was studying was but a part of the whole animal, and that if this was not in perfect condition the conclusions would be subject to all manner of reservations. He worked out in great detail the responses of the salivary and gastric glands to the sight, smell, and taste of food, and showed how the type and quantity of secretion could vary with the kind of food administered. THROUGH PHYSIOLOGY TO PSYCHOLOGY

It is noteworthy that although Pavlov’s work had been directed up to this time towards problems concerning the circulatory and digestive systems, he approached them from the point of view of their nervous control. In 1902 Bayliss and Starling demonstrated the copious secretion of the pancreas in response to the hormone secretin, and Pavlov had to revise many of his conclusions in view of this hitherto unsuspected mechanism for coordination. He foresaw that development for the next few years would be likely to be along chemical lines, and it is probable that his disinclination for this type of work was one of the factors which turned his attention to the nervous system itself. At all events, the next thirty years saw a direct attack on the physiology of the cerebrum whose results transcended in importance anything which Pavlov had yet done. He noticed that an organ could be activated reflexly not only by its normal stimulus, but, under certain circumstances, by all kinds of stimuli not usually associated with it. Thus if a dog was always fed in a routine manner by the same attendant, dressed in the same way, it would begin to secrete saliva before tasting the food, and also when the attendant came without food. In other words an entirely new reflex-a conditioned reflex-had been laid down, the sight of a particular person becoming an adequate stimulus for the secretion of saliva. A salivary fistula enabled Pavlov to assess the quantitative value of the response by measuring the rate of secretion, and he showed how this could be brought about by stimuli applied to any sense-organ. Once the method of producing conditioned reflexes had been established, the next step was to investigate their properties-how they were modified by intercurrent stimuli and the laws determining how they could be reinforced, destroyed, or inhibited. The fruitfulness ofexperiments on inhibitory phenomena alone was surprising, and Pavlov showed, among other things, how inhibition could be built up so strongly as to produce sleep. The technique of the experiments is further illustrative of Pavlov’s genius in obtaining reliable information about a single organ from the intact animal. This time the problem was not surgical, but rather one of designing apparatus and perfecting routine. The brain was "isolated " by keeping the animal under absolutely constant conditions and

ensuring that the experimental stimuli to which it subjected were the only unusual events in its life. This required extraordinary precautions including the building of special laboratories and the rigid training of assistants. It might have been contended, was

with

some

show of

reason

in

regard

to his earlier

digestion, that Pavlov owed his success to his amazing manual dexterity and operative technique, which were the envy of his assistants. In considering his work on conditioned reflexes, however, it becomes apparent that the factor determining the outcome of his researches was always his method of attacking a problem. His life was literally devoted to the search for truth, and in achieving experiments

on

his ends he used

no

instrument which he had not

perfected to the highest possible degree. " A superb experimenter, combining the talent of a magnificent surgeon and a shrewd observer; a dynamic lecturer, surpassed only perhaps by Maximot in logic and the use of language ; a powerful thinker, never interested much in priority, never influenced by 2 any authority, he understood only the logic of facts." It is unnecessary nowadays to stress the value of this objective method ofapproach in the study of the mind. Pavlov believed that all acquired habits and training depended on chains of conditioned reflexes, and that his experiments on dogs provided the clue to the type of activity taking place in the human cortex. By comparing the reactions of different animals to his experiments, the readiness or otherwise with which they formed conditioned reflexes, and the subsequent stability of the reflexes, he was able to divide dogs into four groups which bore a close resemblance to the " choleric, phlegmatic, sanguine and melancholic " temperaments of man. By associating one kind of response with a conditioned stimulus of certain characteristics, and an incompatible type of response with a closely related but slightly different stimulus, he trained his dogs to If an astonishing pitch of discriminative ability. overtaxed, for instance by persistently having to differentiate between two musical notes varying by only a few vibrations, they broke down and became definitely neurotic, losing temporarily all vestige of their training. Inhibitory reflexes were always the greatest sufferers under such conditions. Clearly this was leading Pavlov into the realms not only of normal but of abnormal psychology. He related the original " type" of dog to the disturbance most likely to develop, and was able to produce states analogous to hysteria, catalepsy, and many of the neuroses and psychoses. Visitors to Leningrad last year were able to see the groups of orphan babies whose development he was observing, and the patients he was investigating in the Psychiatric Polyclinic where he had charge of 25 beds. A LEGACY TO SCIENCE

The

of Pavlov’s work has at the time of his death he was the centre of a vast and still growing organisation of research which had sprung from his first modest experiments. It is doubtful whether the usefulness of the methods he has introduced will ever be exhausted, while the results so far attained have already made a permanent impress on several branches of learning, including some previously immune to never

logical development

faltered, and

experiment. 2 Stavraky, G. W. : Arch. Neurol. and Psychiat., 1935,

Most of the biographical data in the present obtained from this account of Pavlov’s life. The taken at the Rockefeller Institute, during a visit photograph to New York, by Mr. Louis Schmidt.

xxxiii., 1082.

sketch

were

was

566 His powerful, yet lovable personality, will not be forgotten by those of the present generation, while the intense loyalty and admiration he evoked in all worked with him bids fair to make that personality legendary. Known in every civilised country in the world, he was awarded many foreign and international distinctions, including the Nobel Prize in medicine and physiology in 1904. In this country he was a foreign member of the Royal Society, whose Copley medal was given to him in 1915, and an honorary fellow of the Royal College of Physicians.

who

MEDICINE AND THE LAW The

Nottingham Nursing-home Trial Nurse Waddingham, an unregistered nurse, was found guilty last week of the murder of Ada Baguley at

a

home carried

on

at

Devon-drive, Sherwood,

Nottingham. In the organs of the dead woman’s body 41/6 grains of morphine hydrochloride were found. One grain was a possible fatal dose. The jury may well have been satisfied that Ada Baguley died on Sept. llth of morphine poisoning : they had also to be satisfied that the accused administered the morphia and administered it with intent to murder. A will made by the deceased on May 7th in favour of the accused was suggested as a motive. When told, on Sept. 24th, that morphia had been found in the body, Nurse Waddingham said : "I have never given Miss Baguley any morphia : I have never had any in the house.... Apart from the medicine prescribed by the doctors and aspirin, she has had no other medicine." Later she admitted that she had morphia, but she said that Dr. Manfield (the deceased’s medical attendant) had prescribed it and she had not mentioned the fact because he asked her not to. This statement Dr. Manfield denied. There was a further vital conflict of evidence between the accused and the medical attendant. The accused said that on August 27th Dr. Manfield gave her 6 tablets which she knew were morphia. Dr. Manfield said that he did not and that there was nothing in the patient’s condition which would lead him to leave morphia at the home. Inasmuch as the defence contended that the accused administered the morphia to alleviate violent pain, it was important that Dr. Jacob, who had attended Miss Baguley previously, visited the patient in the third week of August and saw no reason to prescribe morphia. The drug indeed, according to the accused, was mentioned for the first time on August 27th. She said that on Sept. 2nd Dr. Manfield gave her 4 more tablets of morphia, without being asked and without asking whether she had used any of the previous 6. Dr. Manfield denied this too. Nurse Waddingham said she had given the first two tablets to the deceased on Sept. 7th. She said Miss Baguley had been poorly from some date in August and one of the symptoms was a severe abdominal pain. She gave the morphia tablets for three nights because Ada Baguley suffered sharp abdominal pains, yet on Sept. 10th she cooked her a heavy meal of pork (two helpings), baked potatoes, kidney beans, and fruit pie. The patient died next morning. Dr. Manfield was sent for: he found the body still warm : rigor mortis had not set in. He certified cerebral haemorrhage as the cause of death. This, as the post-mortem examination showed, was wrong. Mr. Justice Goddard remarked that no blame could here be attached to the doctor for the error. If a patient dies of a stroke,

the doctor can act on what he is told and he can but ask those who were present at the death and form his own opinion. The doctor was dealing with a patient suffering from a disease with which apoplectic disorders could be connected, and he was told that she had suffered from strokes before. There were, as the judge observed to the jury, many points at which the evidence was in Nurse Waddingham’s favour. The inconsistencies in her story and the conflict between her evidence and that of Dr. Manfield seem to have established her guilt. One point of special significance was the introduction of evidence that Ada Baguley’s mother, an inmate of the same home, had apparently died of a poisonous dose of morphine. Dr. Roche Lynch described the discovery of pseudomorphine in her exhumed body. How was this evidence of another death legally admissible on the charge in respect of Ada Baguley alone ? We noted in this column a few weeks ago the case of R. v. Mortimer, where a soldier who stole a car ran down a girl on a bicycle and was charged with murder. Although strictly the witnesses should have spoken only of this incident, the court admitted evidence that, earlier and later, the soldier had driven the car at other people on bicycles. These facts were held to be admissible in order to show systematic purpose and to negative the defence of accident. So also in the Baguley trial the evidence of a parallel case was allowed in order to prove intent. The jury was warned (for what such warnings may be worth) that the evidence of Mrs. Baguley having died of morphine poisoning was not to be accepted by them as showing that Nurse Waddingham was a woman who poisoned other people. The evidence of the mother’s death was material, said the judge, only in this way-if the jury thought the administration of morphine to the mother might not have been innocent, they could ask themselves whether the giving of the drug to the daughter was done with the innocent intention to relieve pain or with the criminal intention of taking life. Whether juries can master these subtleties or no, such is the law. The same point arose in the Armstrong case in 1922. On a charge of murder by arsenical poisoning in the month of February, it was proved that the prisoner had arsenic in his possession both before and after that date. His defence was that death was due to suicide and that his possession of arsenic was for the innocent purpose of killing weeds. Evidence that he tried to poison somebody else with arsenic in October was held admissible as tending to show that the possession of the weed-killer at the earlier date was not for an innocent purpose. There is to be an appeal in R. v. Waddingham. It has been stated in the daily press, on the authority of the solicitor for the defence, that one ground of appeal will be the fact that the judge told the jury it was either murder or nothing and did not deal with the possibility of manslaughter through the negligent administration of morphia to the patient. The discussion on this and other points must be awaited.

Hospital’s Liability

for Child Patient

A verdict of 500 damages (with costs) was entered last week against the Rochester and Chatham Joint Hospital Board, as managers of St. William’s Hospital, Rochester, in an action for damages for personal injuries to a child patient. A boy of 7 was received in the scarlet fever ward on the ground floor. On the afternoon of his first day in the ward, having been placed in a bed a few feet from a window, the lower part of which was open, he somehow sustained