TRANSACTIONS OF SECTION I. 803 



tracted with alcohol, and if this alcoholic extract bo allowed to dry, and then be 

 redissolved in a little water or salt solution and injected into the blood of a dog, 

 the results which are obtained, considering the rainute amount of substance added 

 to the blood, are certainly most extraordinary. The nervous centre which regulates 

 the action of the heart is powerfully affected, so that the heart either beats very 

 slowly and weakly, or the auricles may even for a time stop beating altogether. 

 If, however, these inhibitory influences be cut oft" by division of the vagi nerves, the 

 effect of the poison upon the heart is of an opposite character. There is great accele- 

 ration of the rate of the beat and a great increase of force. This is accompanied by 

 a strongly marked influence upon the blood-vessels, and especially upon the arte- 

 rioles. The walls of these are chiefly muscular, and the drug exerts so powerful 

 an action upon this muscular tissue as to cause the calibre of the vessels to be 

 almost obliterated. The heart beint; thus increased in force and accelerated, and 

 the calibre of the vessels almost obliterated, the result is to raise the pressure of 

 the blood within the arterial system to an enormous extent, so that from a blcod- 

 pressure which would be sufficient to balance a column of some four inches of 

 mercury the pressure may rise so high as to be equal to a column of mercury of 

 twelve or more inches. 



This result is obtained, as we have seen, by a verv minute dose. We have to 

 do here with a substance which is as potent, although in a different direction, as 

 strychnia. "Whether it is a useful substance formed by the supra-renals from 

 materials furnished by the blood, and subsequently gradually used in the economy 

 for the virtue of its action upon the circulatory system, or whether it is to be 

 regarded as a poison, formed by the tissues during their activity and carried by 

 the blood to the supra-renals, there to be rendered innocuous, we do not as yet 

 certainly know. These are important points which mu.st form the subject of 

 further "investigation. But, however this may be, it is clear that in this gland 

 also we again meet with an instance of the physiological importance of what Sir 

 Frederick Bramwell called the ' next to nothing.' 



I will give one more instance, taken this time from a gland which is provided 

 with a duct. Until quite recently it might have been thought that there waa 

 nothing very obscure regarding the functions of the pancreas. The pancreas is a 

 digestive gland which lies below and behind the stomach : it has a duct which 

 carries its secretion into the beginning of the intestine, and that secretion acts 

 powerfully upon all constituents of the food, digesting starch, meat, and fat. It 

 was not supposed that the pancreas had any other function to perform. Animals 

 can live without this secretion, and to a large extent can continue to digest and 

 absorb their food much as before ; for it has been possible to divert the secretion 

 from the intestine and to collect it at the surface of the body; and it is found 

 under these circumstances that, although the food is not quite so readily digested, 

 nevertheless the animal does not materially suffer from the lack of the secretion. 

 It was discovered, however, a few years ago (by v. Mering and Minkowski) 

 that if, instead of merely diverting its secretion, the pancreas is bodily removed, 

 the metabolic processes of the organism, and especially the metabolism of carbo- 

 hydrates, are entirely deranged, the result being the production of permanent 

 diabetes. But if even a very small part of the gland is left vrithiu the body, the 

 carbohydrate metabolism remains unaltered, and there is no diabetes. The small 

 portion of the organ which has been allowed to remain (and which need not even 

 be left in its proper place, but may be transplanted under the skin or elsewhere) 

 is sufficient, by the exchanges which go on between it and the blood generally, to 

 prevent those serious consequences to the composition of the blood and the general 

 constitution of the body which result from the complete removal of this organ. 

 Now, some years ago it was noticed by Kiihne and Sheridan Lea that, besides its 

 proper secreting structure composed of tubular alveoli, lined by granule-containing 

 cells, there are highly vascular patches of peculiar epithelium-like cells scattered 

 here and there in the substance of the pancreas, which are wholly unconnected 

 with the ducts and, so far aa one can judge, with the secretion of the gland. We 

 do not know anything whatever about the function of these patches, although 

 from their vascularity it is extremely probable that they are not without impor- 



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