DISCOVERY 



187 



The pituitary gland at the base of the brain has also 

 been credited with an internal secretion of wide- 

 reaching power. If its secretion is deficient in early 

 life, a dwarf-like condition is the result ; if, conversely, 

 it be excessive, the individual grows up a giant (gigan- 

 tism). If the activity of the gland is deficient in adult 

 life, a distressing and progressively fatal disease, called 

 acromegaly, is induced. In this condition the bones 

 of the face, hands, and feet become hugely overgrown. 



From the posterior part of the pituitary body there 

 has been extracted a substance (pituitrin') which is 

 a powerful stimulant to the uterine muscle, and as such 

 is dailv used by obstetricians. 



Insulin and Diabetes 



Within the last two years another of these internal 

 secretions, orhormones,has been identifiedand isolated. 

 The term " insuline " had been suggested by Sir 

 Edward Schafer before 1916 as the name of the sub- 

 stance which was manufactured by the islands of 

 Langerhans in the pancreas and which, carried by the 

 blood to the tissue, enabled them to oxidise the sugar 

 of the blood to carbon dioxide and water. When, 

 owing to disease of the pancreas, this internal secretion 

 was deficient or absent, sugar accumulated in the blood 

 and was excreted by the urine — a condition known as 

 diabetes. At Toronto University a number of workers, 

 directed by the head of the Department of Physiology 

 there, have recently succeeded in extracting from the 

 islands of a healthy pancreas a substance which, if 

 injected into the blood of a diabetic animal, will clear 

 it of its blood-sugar and greatly prolong its life. When 

 administered to human beings suffering from diabetes 

 the effects have been equally striking. 



At the close of 1922 more than fifty diabetics had 

 been immensely benefited and had their lives pro- 

 longed by this insulin treatment. Diabetes is most 

 fatal in young children. There are children living 

 to-day who some months ago were moribund from 

 diabetic coma. 



Insulin has been captured and found incarnated 

 in the pancreas. From this it has been extracted, 

 purified, and bottled. 



The Black Death 



Another excellent example of the rendering definite 

 what was before of the vaguest is the recent discovery 

 of the cause of plague, the pestilence, or Black Death. 

 In the fourteenth century the great surgeon of Avignon, 

 Guy de Chauliac (1300-1370), attributed the plague 

 to a conjunction of the planets Saturn, Jupiter, and 

 Mars in the sign of Aquarius on March 24, 1345. About 

 the same time the Jews in Germany and Switzerland 

 were suspected of poisoning the wells and were in 

 consequence persecuted and massacred. In the four- 



teenth century the medical faculty of the University 

 of Paris was asked to deliver an opinion on the nature 

 and origin of plague, but a very great deal that it pro- 

 mulgated was absolutely fatuous as regards protection 

 or cure. One thing only was recommended that is 

 interesting in the light of to-day, namely the fumiga- 

 tion of houses by the burning of aromatic herbs and 

 woods. Only as recently as 1894 was the vera causa 

 of the Black Death, one of mankind's most terrible 

 traditions, discovered by two Japanese doctors, 

 Yersin and Kitasato, and named the Bacillus pesiis. 

 It was soon isolated in pure cultures, grown in arti- 

 ficial media, and its toxins and antitoxins became 

 chemical entities. 



The source of the plague was shown to be a bacUlus, 

 a most minute vegetable parasite, which growing in 

 bodies of certain animals, rats and other rodents, 

 could give rise to a virulent poison (pestiferin) which was 

 carried to all parts by the circulating blood. It was 

 further shown that man became inoculated by fleas 

 which had been feeding on the bacilli containing blood 

 of rats. Thus were revealed the several links in that 

 long chain which had the Bacillus pestis at one end and 

 man at the other. It took mankind three thousand 

 years to come to a knowledge of the truth regarding 

 the cause and manner of the spreading of plague, 

 to a knowledge of that chain of cause and effect which 

 connects microbe and man in the dire relationship of 

 the plague-stricken. 



Influenza 



Very probably some of the great epidemics of the 

 Middle Ages were in reality what we now call Influenza, 

 its very name being only the Italian for influence, a 

 something inscrutable but omnipresent, mysterious 

 in the last degree. The usual expressions were in 

 vogue — it was a corruption in the air, a miasma, an 

 exhalation, and so on ; until in 1892 the bacteriologist 

 Pfeiffer isolated the organism of influenza and named 

 it the Bacillus injluenz.-e. Not the air, then, but the 

 microscopic fungi it may hold for evil influence, con- 

 stitute the true cause of influenza. The influence is 

 now materialised, nay, indeed, is isolated and sealed 

 down under glass for the inspection of trained eyes. 

 Thus by the microscope are these deadly powers of 

 the air one by one distinguished from each other and 

 identified each by its particular malignancy. 



The story of the discovery of the telescope, how it 

 was bound up with that wonderful emancipation of 

 the human spirit from the thraldom of medieval ignor- 

 ance and the hatred of scientific light, has been told 

 us bv many learned men ; but I venture to think that 

 the discovery of the microscope, which still awaits 

 its poet, was one fraught with many more beneficent 

 results for humanity. By its scrutiny the invisible 



