Oct. 4, 1877] 



NA TURE 



485 



unction is strikingly illustrative of this fact. They 

 suggest that the nervous impressions sent from the cen- 

 tres to the peripheral surface when they reach the peri- 

 pheral surface, as on the surface of the skin, spread out 

 like circling waves, just, in fact, as water spreads out in 

 circles on a pool when a stone is made to impinge on the 

 surface. 



Some other recent investigations on the mode of action 

 of the poisons of the communicable diseases has led me 

 to suspect the source of the symptom which is so com- 

 mon to most of them, and which is known as the atten- 

 dant fever. The fever is of three kinds : primary, 

 reactive, and remittent. The primary fever is that which 

 precedes and attends the eruption of an eruptive disease. 

 The reactive fever is that which succeeds the extreme 

 collapse of an acutely-exhaustive disease like cholera, or 

 an exposure to extreme cold. The remittent fever is that 

 which succeeds upon an acute form of disease, and indi- 

 cates either that there has been secondary absorption of 

 matter from an abraded surface in contact with poisonous 

 substance, or that some fibrinous or pustular matter 

 has formed within the body, as it were, and become a 

 new and permanent centre of infection. 



The first of these forms of fever is, I believe, due to 

 the impression on the nervous centres by the poison in 

 the manner I have described above. 



The second, the reactive fever, is, I believe, due to the 

 same action as that which locally may be induced by 

 extreme cold, viz., by an influx of blood into vessels that 

 have been paralysed, and by a rapid radiation of heat 

 from extensive surface of blood. 



The third form of fever, the remittent, has an origin, 

 I believe, specifically its own. I have found that pustular 

 matter and all secretions containing fibrinous or cellular 

 structure have the property, by their presence, of libe- 

 rating oxygen from solution. This extends, as I have 

 found, to blood charged with oxygen, and I am led to the 

 inference that when there is an absorption of such matter 

 into the circulation it causes an undue liberation of oxygen 

 with a quicker combustion, a fever which lasts until the 

 e.xciting matter is itself destroyed and eliminated, and 

 which I does not recur until there is re-absorption of 

 more of the exciting agent. In this physiological mode 

 I should explain all the phenomena of the remittent 

 attack; the cold stage incident to the absorption of the 

 exciting matter ; the hot stage incident to the period 

 when, by its presence, the exciting matter is setting free 

 excess of oxygen ; the sweating stage when, by rapid 

 elimination through the sweat glands, the equilibrium of 

 temperature is restored. 



The study of the glandular theory of the communicable 

 diseases has suggested to me another thought which ob- 

 servation of the diseases fully confirms, viz., that these 

 diseases, like all which have their root in nervous derange- 

 ment, present a distinct heredity. The impression of 

 disease made on a nervous centre is transmitted. There 

 can be no doubt as to transmission of tendency to 

 particular communicable diseases. Any physician in full 

 practice can find any amount of evidence on the fact by 

 simple natural inquiry. Typhoid fever is clearly a disease 

 possessing hereditary transmissible quality. Diphtheria 

 is the same. Scarlet fever is the same, and small-pox I 

 should suspect was once almost universally so character- 

 ised. These facts alone, one of them alone, is sufficient 

 to stamp the origin of the communicable diseases as from 

 the animal body itself. It is certainly one of the best of 

 proofs of the truth of the theory of the glandular origin of 

 the poisons. It will be seen at once by those who look 

 with sufficient patience, that the mode of connection of 

 the diseases in hereditary line is the same as that which 

 connects hereditary qualities of every kind, physical type, 

 mental type, all else that binds many individualities into 

 one family. 



Lastly, the study of the glandular theory of the commu- 



nicable diseases enables me to offer tlie the most rational 

 explanation of the phenomenon of non-recurrence of the 

 diseases after they have once attacked a person suscep- 

 tible to them. It is well understood that, as a rule, a 

 person who has been affected by a communicable disease 

 is not affected a second tiine. To this rule theie are 

 many exceptions, but on the whole it holds good. On 

 my theory the reason of the phenomenon is simple 

 enough. They who are susceptible are born with a 

 nervous impression tending to the production of a glan- 

 dular secretion easily changed into poisonous secretion 

 under the direct action of contact with poisonous matter, 

 or even under the influence of a central nervous de- 

 piession, whereby the glandular function is deranged. 

 But when such a person has passed through the ordeal 

 the tendency, for a time at least, disappears owing to the 

 complete modification of glandular function that has been 

 induced, to the free elimination that has been established, 

 and probably to the change in the nervous matter itself 

 that has resulted from organic modification. Hence the 

 organism becomes susceptible for a time, and if the 

 tendency be not intense that time may mean the whole of 

 the life. Indeed as life advances and nervous suscepti- 

 bilities derived directly from ancestry lapse into individual 

 self-sustained susceptibilities, these tendencies to disease 

 subside as a general fact, and lose their activity if not 

 their existence. 



I turn, in conclusion, to consider for a moment from 

 the view of the glandular theory of the communicable 

 diseases, the practice that is suggested for the suppression 

 of the plagues of mankind. 



It will be seen at once that on this point nothing can 

 be wider than the distance between the idea of contagium 

 as a living self-productive thing, reproductive and inde- 

 pendent, and the theory of the production of the contagium 

 in each aftected person by the force of production of 

 his own secretion. The latest and one of the ablest 

 advocates of contagium vivum. Dr. W. Roberts, says, 

 respecting contagium: — "We know of nothing that ex- 

 hibits the phenomena of growth and multiplication except 

 a thing possessed of life." 



I admit that readily, but my argument is that the pro- 

 cess of secretion is a process of life, and that this living 

 process, perverted as I have described, is amply sufficient 

 to account for the production of all the poisons that exist 

 to cause the communicable diseases, that it accounts for 

 the number of these diseases, and more, that it accounts 

 for the limitation of the number. 



The Glandular Theory in its Applicaiion to Practical 

 Sanitation. 



The practical usefulness of the theory, however, con- 

 sists in its direct application. If the contagium vivum 

 view be true, if the air around us is charged with invisible 

 germs which come from whence we know not, which have 

 unlimited power to fertilise, which need never cease to 

 fertilise and multiply, what hope is there for the skill of 

 man to overcome these hidden foes } Why on some 

 occasion may not a plague spread over the whole world, 

 and destroy its life universally ? 



My theory presents an altogether dilferent aspect. I 

 say to living men and women, it is you who are the pro- 

 ducers of the communicable diseases, or if it be not you 

 yourselves it is one of your lower earthmates in creation, 

 some domestic animal that shares with you the power of 

 producing a poisonous secretion and of giving a here- 

 ditary stamp of production to such poisonous product. I 

 look on the man or animal affected with a contagious 

 disease as one precisely, for the time, in the position of 

 the cobra or other animal that naturally secretes a poison, 

 and recognising this fact I see at once that the danger is 

 all but limited to the person affected. 



Isolate that person from the rest of mankind, take care 

 that his secretions, volatile, fluid, or solid, do not come into 



