A treatise of the rickets being a diseas common to children. Wherin (among many other things) is shewed, 1. The essence 2. The causes 3. The signs 4. The remedies of the diseas. Published in Latin by Francis Glisson, George Bate, and Ahasuerus Regemorter; doctors in physick, and fellows of the Colledg of Physitians at London. Translated into English by Phil. Armin.

CHAP. XIV. The Secondary Essence of this Diseas in the A∣nimal Constitution. (Book 14)

HAving put an end to the examination of the Natural and Vital Constitution, vitiated in this affect, it now remaineth that we make enquiry into the Animal Constitution. And we have already affirmed, that no primary fault doth here occur, and that it is a part of the primary Essence of this Diseas. But whether there lurk in it any secondary vice, that we shal now examin.

But seing that neither the Ancients nor the Modern Writers, who have written of the Animal Faculty, have made any mention of the Animal Constitution, nor in∣deed so much as once attempted a description of it: It may very justly be expected from us, who acknowledg such a Constitution. And seing som wise men do dis∣sent from that description, which may be deduced from

the opinion of Antiquity, and the common opinion con∣cerning the Animal faculty, and otherwise expounding the matter do substitute a somwhat different descripti∣on, we thought good to offer both to the Readers con∣sideration.

According to the former and vulgarly received opi∣nion and description of the Animal faculty, the animal constitution is that affection of the Body which consi∣steth in the generation and due motion of the Animal Spirits. Now by the due motion of the Animal Spi∣rits they understand the excursion of them from the Brain thorow the Nerves like lightning, and again their recourse back to the Brain, whereby they declare unto it what is perceived by the Organs of the outward Sen∣ses.

Others (as we have said) do otherwise explicate this matter. They grant indeed that the Animal constituti∣on doth include the generation and destribution of the Animal Spirits but they say that that swift motion of the Flux and Reflux of the Animal Spirits like light∣ning, is inconceivable in the Nerves, and if it be not unprofitable, yet certainly it is very little necessary to e∣stablish the animal faculty. But instead of this they substitute in time of waking a certain contractive mo∣tion, of a moving endeavor of the very substance of the Brain, of the Spinal Marrow, of the Nerves arising from thence, and of the parts into which they are destributed. And this motion or endeavor pro∣duceth (say they) a certain Tensity in the aforesaid parts, by whose force all the alterations imprinted in those parts by any objects, are communicated to the Brain. For as in a Harp when the strings are stretched to a just pitch, if they be stricken in the most gentle manner at either end, that motion in a moment, at

least a Physical one, runneth to the other end; so they likewise affirm that any Nerve being moved which is duly stretched without the Skull, that motion is exten∣ded to the Brain it self by reason of the continuity and Tensity of the said parts, and there fixeth a certain im∣pression conformable to the caus thereof. But in time of sleep they suppose the Brain, the Spinal marrow, and some of the Nerves to be somwhat loosned. And in∣deed they say perpetually and simply that the foremost connexions of the Spinal Marrow with the Brain re∣main loos continually during sleep; but they grant that the hindermost connexions with the Cerebethi are somwhat extended, as in Night-walkers, and so by that means they do in some sort discern outward objects, but they judg not of them by common sense, but as it were reflected from the memory to the Fantasie. Neither do they suppose it necessary that all the inferior parts of the Spinal Marrow, and therfore the Nerves from thence proceeding should be perpetually loosned during sleep: seeing that most Birds sleep standing upon their feet; seing that respiration in time of sleep doth pre∣suppose the Tensity of some Nerves; and lastly, seing where sleep first steals in, the uppermost Nerves are wholly loosned before the neathermost. As for Dreams they conceive that they proceed from a various and chanceable agitation and commixture of divers impres∣sions treasured up in the memory, which are now again freshly perceived by reason of a retained Tensity in som parts of the Brain. But when in deep and profound sleeps no dreams are represented, then they say that the whol Brain is loosned.

Now whether the former opinion or this latter be most agreeable to truth, for the present we do not much care; Neither do we here undertake to determine this

Controversie, seing that the Animal faculty doth exer∣cise his function both waies, from the same causes, and that the secondary vice doth happen by this affect in the Animal Constitution almost after the same manner. For first, as for the generation of the Animal Spirits, whether the former or the latter opinion be true, it wil be all one; becaus we find no fault in the Brain (unless perhaps some other Diseas be conjoyned) wherin each opinion supposeth the Animal Spirits to be generated. For we have shewed above that the Head ought not to be numbred among the first affected Parts, and that the internal and proper actions therof are not viciated in this Diseas. Then secondly, As for the destribution of the Animal Spirits, whether it be perfected backwards and forwards by that rapid and sudden motion like lightning, or by a motion only made forwards and that too gentle and slow, commonly the same fault occurreth in this Diseas.

For first, Seing that that supposed rapid motion of the Animal Spirits is caused by their passage into the first affected Parts, namely, through the Spinal Martow without the Skul, through the Nerves from thence pro∣ceeding, and through the parts into which those Nervs are destributed; and seing that all these parts in this affect do labor with a cold distemper, with a paucity and dulness of inherent Spirits, the due swiftness of that motion must needs be somwhat retarded. For a cold di∣stemper, as also a benummedness and penury of Spirits are repugnant to any motion, excepting a constrictive; some may say that the opinion propounded in the first place doth suppose a wonderful activity and subtilty of the Animal Spirits, wherby they can easily overcome this repugnance. But, however it may be, seing that the parts react through which the Spirits have their passage,

and labor to communicate their coldness and dulness to them, they must needs in some degree retard that acti∣vity of the Spirits, lessen their subtilty, and somwhat in∣tercept that expedite transition. Wherfore this opinion being supposed as true, the Animal Constitution will be viciated in this affect, in regard of the retundation of that motion of the Spirits. And that secondarily, seing that this motion is not interrupted by the primary fault of the Animal Spirits, but by the fault of the first affe∣cted Parts, as hath been said in like manner in the O∣pinion last proposed, wherin the motion of the Spirits is supposed to be peaceable and gentle, they must needs whilst they are somwhat slowly transmitted through the first affected parts, contract some viciosity from the de∣praved inherent Constitution of those parts, for the same Reasons which we alleaged in the Question imme∣diatly preceding. It will be therfore according to this Opinion also, a Secondary vice in the destribution of the Animal Spirits,

Again, As for the Tensity of the very substance of the Brain, of the Spinal Marrow of the Nerves and the Nervous parts in time of waking, which is supposed in the latter Opinion before propounded, there must needs be some defect of a due Tensity in the Spinal Marrow without the Skull, in the Nerves arising from thence, and in the parts unto which they are destribu∣ted. For first, A cold and moist distemper is repugnant and advers to that due Tensitiy, so also is that dulness and penury of inherent Spirits; wherwith the Parts are without controversie rendred slothful, and less apt to perform the Animal Actions; the contrary wherof hap∣peneth, when the aforesaid parts obtain their due Tensi∣ty. Secondly, It is manifest by what hath been said, that the Tone of these parts is somwhat viciated in this

affect, by reason of their exceeding loosness, slipperiness, softness, weakness and internal lubricity, which qualities do most evidently enfeeble the just Tensity of the said Parts. Although therfore that the Brain in this affect do for his part yield a due and just influx, yet it is scarce possible, nay it is altogether impossible, that it should communicate that Tensity in a sufficient degree to to the Spinal Marrow without the Skull, to the Nerves from thence proceeding &c. because of the distemper, benummedness and penury of the inherent Spirirs. Thirdly, The Symptoms in this Diseas that relate to the Animal faculty do most clearly confirm the same thing. For Children afflicted with this Diseas do from the very beginning therof (if they be compared with others of the same age) move and exercise themselves very weakly, and are less delighted in manly sports: but up∣on the progress of the affect, they are avers from any vehement motion, as they stand upon their feet, they reel, wave, and stagger, seeking after somwhat to sup∣port them, and can scarce go upright; neither take they pleasure in any play unless sitting or lying along, or when they are carried in their Nurses Arms: Finally the weak Spine is scarce strong enough to bear the bur∣den of the Head, the Body being so extreamly extenu∣ated and pined away. All which things do abundantly demonstrate that the Tensity of the parts subservient to motion is less rigid in this affect than is justly requisite in time of waking. If therfore that due Tensity in time of waking be a part of the Animal Constitution, which we here suppose, that being viciated must with∣out all doubt necessarily constitute a Diseas in the Ani∣mal Constitution; and seing that this fault hath no primary dependance upon the Brain it self, but upon the inherent Constitution of the first affected parts, it

ought in all Reason to be reputed a Secondary fault in respect of the Animal Constitution.

Yet here we meet with a scruple. Som may demand, Why the sens as well as the faculty of motion is not viti∣ated in this affect? The reason is plain, a far greater tensity, strength and vigor of the Nervs is required to exercise the motive then the sensitive faculty. For almost the gentlest motion of the Nervs is sufficient for sense; but not for motion. So you may observe in the motion of any Joynt, that the Muscles which move it are very hard and stiff, but that hardness being remitted, yet the sensation is easily performed. Nor doth that any way hinder, because that somtimes in the Palsy the sense is somwhat stupified, and the motion remaineth: for the Palsy is an affect very different from this; for in that the primary fault resides in the very Animal Constituti∣on, therfore it may so fal out, that both the sense and the motion may be equally affected. Besides, when perhaps one Nerve doth want the du influx of the Brain, and ano∣ther which is extended to the muscles of that part doth enjoy it, it may be, that for this cause also the sense may be abolished, and yet the motion may continu; although this case is not so frequent, and that the motion is more usually taken away, the sense remaining. But we have said enough concerning this matter. And thus at length we have produced those things which we have meditated of the integral Essence, both primary and secondary of this Diseas; and that with as much perspicuity as a mat∣ter so difficult and unsearcht into, would bear: In the next place we shal address our selvs to the examination of the causes of this Diseas.