721 



SPINA BIFIDA. 



SPINAL IRRITATION. 



722 



potent plant, is sometimes mistaken and given for the other. It 

 contains an alkaloid called spigelina, which is volatile, somewhat like 

 nicotina, the effects of which it also resembles, causing formidable 

 narcotic symptoms, to which lemon-juice, sugar, or carbonate of potash 

 ia said to be an antidote. 



SI'IXA BI'FIDA, or cleft-spine, is a disease commencing in foetal 

 life, and which consists in an imperfection of the posterior part of the 

 spinal canal. It is almost always accompanied by an excessive secre- 

 tion of spinal fluid, and in these cases it may be regarded as a disease 

 of the same kind affecting the spinal canal as that which, existing in 

 the skull, constitutes hydrocephalus. The two are indeed not 

 un/requently coincident ; and spina bifida is sometimes called hydro- 

 rachis. 



The arch of each vertebra [SKELETON, in NAT. HIST. Div.] is 

 developed and ossified in two pieces which meet behind in the middle 

 line at the base of the spinous process. This is also developed in two 

 lateral portions which subsequently unite together and with the arch, 

 so as to form the one piece of bone which we find in the adult closing 

 in the back of the spinal canal. This development and union of the 

 arches of the vertebra; goes on during an early period of foetal life, 

 while the spinal column is growing rapidly, and the fluid of the spinal 

 canal and arachnoid sac is being constantly secreted. If this fluid be 

 secreted in an unnaturally large quantity before any or a part of the 

 arches of the vertebra: are completely ossified, it may exert such 

 pressure upon them as to separate their component parts, and produce 

 a permanent aperture in the back of the spinal canal, through which 

 a sac containing the excess of fluid will protrude. Or if the develop- 

 ment and ossification of any or all of the arches take place more slowly 

 than it should, then a secretion of not more than the ordinary quantity 

 of fluid may suffice to keep them permanently open. A cleft spine 

 will thus be produced without the watery tumour ; but the openness 

 of the spine will generally in cases of this kind lead to the secretion of 

 an unnatural quantity of the spinal fluid ; for it seems a general law 

 that, other things being equal, the quantity of fluid secreted in each 

 part ia inversely proportionate to the resistance offered by the walls of 

 the cavity into which it is poured. 



Spina bifida is almost always characterised by a tumour situated 

 over the defective vertebrae, globular, elastic, and fluctuating, often 

 attached by a narrowed base, and varying in size according to the 

 extent of the fissure in the spinal canal. It is usually covered by 

 healthy skin, and consists of the dura mater, and one or more of the 

 other membranes of the spinal cord, protruded in .1 sac through the 

 space between the separated arches, and filled by a clear serous fluid. 

 ( In pressing-such a tumour the patient may become insensible, or be 

 convulsed ; for the fluid within it communicating with that within or 

 around the brain and spinal chord, the pressure made upon it is felt 

 with equal force by the whole of those organs. The parts of the body 

 below the tumour are often paralytic, not from the pressure of the 

 fluid, for that is equally diffused, but from disease of the cord coinci- 

 dent with that of the arches. 



Spina bifida is most common in the lumbar and sacral regions, in 

 which the vertebral arches are latest completed : it is most rare in the 

 neck, and is there also most dangerous, because of the great number of 

 nerves which, by the coincident disease of the spinal cord, may be 

 paralysed. It does not commonly interfere with the general health : 

 but by the friction to which, when the tumours are large, the skin is 

 subjected, and by the distension produced by the increasing secretion 

 of fluid, the sac is liable to inflame and ulcerate, till, exposing the 

 spinal cord, or its membranes, death is produced by their inflamma- 

 ti"i> ; or, the quantity of fluid secreted may be so great as to produce 

 death by its pressure on the cord and brain, in a manner similar to 

 that in which hydrocephalus often terminates. 



In one of these modes, spina bifida, when accompanied by excessive 

 secretion, almost always terminates fatally, though patients may survive 

 with it for ten or even twenty years. Life may generally be prolonged 

 by maintaining a gentle even pressure upon the tumour, so as to 

 supply the necessary resistance to the effusion of more fluid. In a 

 few cases a repeated evacuation of the fluid, and then firm pressure 

 upon the sac, has been found successful ; and lately, M. Tavignot has 

 related some cases which he cured by slicing off the tumour, and 

 instantly bringing together the edges of the mouth of the sac, and so 

 holding them till they had united and formed a firm cicatrix. 



That just described is by far the most common form of spina bifida ; 

 others more rare are those in which not the arches only, but the bodies 

 of the vertebra; also are cleft, the two lateral portions in which each in 

 developed being kept apart, so that a portion of the spinal canal is 

 open iivfront towards the cavity of the abdomen. Some differences of 

 character also depend on the seat of the fluid secreted : it is generally 

 in the sac of the arachnoid, but sometimes is in the tissue of the pia 

 mater, or in both it and the sac, or, yet more rarely, in the central 

 canal of the spinal cord. 



SI'IXA VENTO'SA ia a term now obsolete, which was applied by 

 old surgeons to abscesses in bone, accompanied with excessive swelling, 

 and then to nearly all the diseases indiscriminately in which either 

 bones or joints become enlarged. 



SPINACH. One of the species of this genus, the S. oJeracca, the 

 common spinach, is well known on account of its use in the kitchen. 

 It bo an herbaceous stem one or two feet high, branched, and hollow ; 



ART* AXD SCI. DIV. VOL. VI r. 



arrow-shaped leaves; male flowers in long spikes, abounding with 

 pollen ; female flowers on another plant, axillary, herbaceous, and small. 

 The fruit is a small round nut, which is sometimes very prickly. 



There are two principal varieties cultivated in gardens, the prickly- 

 fruited, with triangular, oblong, or sagittate leaves, and the smooth- 

 fruited, with round or blunt leaves. The former is considered the 

 hardiest, and is therefore employed for winter culture ; the latter is 

 used for summer crops. Of these varieties there are several sub- 

 varieties, varying in the size, thickness, and shape of their leaves. 



For the winter crop the seed is sown at the beginning of August. 

 A light, dry, rich soil should be preferred, and, if possible, in a 

 sheltered situation. When the plants have put forth two pair of leaves, 

 the ground should be hoed and the plants thinned. By October or 

 November the outer leaves of the spinach are fit for use. In February, 

 when fine weather occurs, the plants should be again attended to, 

 cleaned, and thinned out, and in this way it may be made productive 

 till April or May, by which time the summer sort will be ready. The 

 first sowing of the round-leaved spinach or smooth-fruited should take 

 place at the end of January in some sheltered border. This crop 

 should be successively thinned out till the plants are eight or ten inches 

 apart. Successive sowings may be made, in order to ensure a constant 

 supply in February, March, and April, and, if desirable, these sowings 

 may take place between rows of cabbages, &c. 



Spinach is often sown in narrow drills, which is rather more trouble- 

 some at first, but this is made up for by the facility with which 

 clearing, thinning, and gathering are afterwards accomplished. 



For preserving seed, those plants which are of the most stocky 

 growth should be selected. The winter crops run up soonest, but seed 

 may be obtained from spring crops in July and August. The new 

 seed is the best for sowing, although it will keep very well for a year. 

 When the plants are saved for seed, the male plants, which are easily 

 distinguished by their flowers, may after fertilisation be drawn and 

 thrown away. 



Spinach is sometimes grown by the farmer for the purpose of 

 obtaining a crop of seed for the uses of the gardener. In the selection 

 of land for this purpose, care should be taken that it is finely prepared 

 by ploughing and harrowing in the early spring, and some well-rotted 

 dung should be ploughed in where the soil is not of the best quality. 

 When the spinach has blossomed, the male plants should be drawn 

 out, which serve at this time as excellent food for pigs, and might be 

 given to other animals with advantage. There is much uncertainty 

 about this kind of crop; sometimes, however, it turns out very 

 advantageous. 



SPINAL IRRITATION. This term has been applied to those 

 functional disorders of the spinal cord and its nerves, which do not 

 readily fall under the definitions of diseases of the same organs having 

 more precise symptoms. Under the heads TETANUS, CHOREA, Hys- 

 TEBIA, NEURALGIA, HYDROPHOBIA, and PARALYSIS, will be found de- 

 scriptions of definite derangements of the spinal cord and its nerves. 

 But there is a general state of the nervous system in which some of 

 the symptoms of one or all of these diseases may occasionally be pre- 

 f ent, and in which there is very commonly present, pain in the spinal 

 column induced or increased by pressure or percussion. To this state 

 the term " spinal irritation " has been applied. What the precise con- 

 dition of the nervous system is in this disease it is impossible to say, 

 but the general theory of its nature is that the spinal cord at some one 

 or more points is congested, and that this congestion acts upon the 

 sensitive or motor nerves proceeding from this part of the cord, 

 and gives rise to the pains^ spasms, and other anomalous symptoms 

 complained of by the patient. This condition is not unfrequently 

 referred to hysteria, but as it may come on in the male as well 

 as the female, there is evidently an impropriety in the use of this 

 term. 



It would be quite impossible to describe here all the nervous 

 symptoms that may be referred to spinal irritation. Wherever nerves 

 of motion and sensation are distributed they may become disordered, 

 and thus there is no organ or part of the body that may not be the 

 seat of excessive pain or paralysis of sensation, of spasmodic or con- 

 vulsive action, and of a paralysis of motion. Such symptoms when 

 they are not fixed, and are connected with pain on pressure of the 

 spinal cord, are said to depend on spinal irritation. Whether these 

 symptoms depend on a morbid condition of the spinal cord, or of the 

 muscular or nervous tissue, or of the blood, are still questions 

 admitting of discussion. 



The treatment of these cases has been directed very much by thn 

 theory held with regard to the cause of the nervous symptoms. Tin > f 

 who advocate the theory of congestion of certain portions of the cord, 

 recommend the employment of counter-irritants over the tender part 

 of the spine, whilst those who believe that they arise from an under 

 nutrition of the nervous and muscular tissues, recommend a treatment 

 addressed to the restoration of the nutritionary powers of the system. 

 Those who think the blood is the source of the disorder, likewise adopt 

 the same general principles of treatment. 



Whatever may be the theoretical views held with regard to the 

 nature of the symptoms, known under the name of spinal irritation, 

 there seems to be a general agreement that they come on in asthenic 

 states of the system, and that antiphlogistic measures must not be had 

 recourse to without great caution. 



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