PULMONATA-PULSE. affording a convenient means of attaching the subjects. The pulpit (in Arabic, mimber forms weight. Theoretically, the larger the number of movable pulleys in one combin- PULMONA'TA, an order of internal and rudimental. PULNEYS, a range of hills in the Madura district of the Madras Presidency of India. The average height of this range is about 7500 feet above the level of the sea. It possesses peculiar advantages for the establishment of a sanitarium. The climate is one of the most equable anywhere to be found, the variation of the thermometer during twelve months in a (From Parker's Glossary.) closed room without a fire being observed to be Pulpit (Fotheringhay, Northamptonshire, 1440 A. D.). no greater than between 58° and 62°. At present, there are only a few European residences built on these hills. PULPIT (Lat. pulpitum), an elevated tribune or desk, from which sermons, lectures, and other solemn religious addresses are delivered. In great churches, the pulpit is commonly placed against the wall, or in juxtaposition with a pillar or buttress. Originally it would appear to have been used chiefly for the singing, chanting, or recitation which form part of the public service, and was a kind of stage sufficiently large to accommodate two or even more chanters. For the convenience of the hearers, this stage began to be used by the bishop, priest, or deacon, for the delivery of the homily; and thus by degrees a tribune expressly suited to the latter use alone came to be introduced. In some of the older churches, the ambo or pulpitum is still used for the chanting of the Gospel and Epistles. In Catholic churches, the pulpit is generally distinguished by some religious emblems, especially by the crucifix; and the pulpits of the Low Countries and of Germany are often masterpieces of wood-carving, the preaching-place in some of them forming part of a great artistic group, as of the Conversion of St Paul, the Vocation of Peter and Andrew, the Temptation of Adam and Eve, and other similar one of the scanty appliances of Mohammedan worship. PULQUE, a favourite beverage of the Mexicans and of the inhabitants of Central America, and some parts of South America; made from the juice of different species of Agave (q. v.), which is collected by cutting out the flowering-stem from the midst of the leaves in the beginning of its growth, and scooping a hole for the juice. From this cavity, large quantities of juice are removed daily for months. The juice is an agreeable drink when fresh, but is more generally used after fermentation, when it has a very pleasant taste, but a putrid smell, disgusting to those unaccustomed to it. Pulque is retailed in Mexico in open sheds called Pulquerias, which also serve for dancing-rooms. When mixed with water and sugar, and allowed to ferment for a few hours, it forms a beverage called Tepache. A kind of spirit is also prepared from it. PULSE (Lat. puls), a name for the edible seeds of leguminous plants, as corn is the name for the edible seeds of grasses. Peas and beans are the most common and important of all kinds of pulse; next to them may be ranked kidney-beans, lentils, chickpeas, pigeon-peas, &c. Legumine (q. v.), a very nitrogenous principle, abounds in all kinds of pulse. Legumine forms a thick coagulum with salts of lime, wherefore all kinds of pulse remain hard if boiled in spring-water containing lime. The best kinds of pulse are very nutritious, but not easy of digestion, and very apt to produce flatulence. PULSE (Lat. pulsus, a pushing or beating). The phenomenon known as the arterial pulse or arterial pulsation is due to the distention of the arteries consequent upon the intermittent injection of blood into their trunks, and the subsequent contraction which results from the elasticity of their walls. It is PULTOWA-PULU. pera ptible to the touch in all excepting very minute arteries, and in exposed positions, is visible to the eye. "This pulsation,' says Dr Carpenter, involves an augmentation of the capacity of that portion of the artery in which it is observed; and it would seem to the touch as if this were chiefly effected by an increase of diameter. It seems fully proved, however, that the increased capacity is chiefly given by the elongation of the artery, which is lifted from its bed at each pulsation, and when previously straight, becomes curved; the impression made upon the finger by such displacement not being distinguishable from that which would result from the dilatation of the tube in diameter. A very obvious example of this upheaval is seen in the prominent temporal artery of an old person.'—Principles of Human Physiology, 4th ed., p. 492. The number of pulsations is usually counted at the radial artery at the wrist, the advantages of that position being that the artery is very superficial at that spot, and that it is easily compressed against the bone. In some cases, it is preferable to count the number of contractions of the heart itself. The qualities which are chiefly attended to in the pulse are its frequency, its regularity, its fulness, its tension, and its force. The frequency of the pulse varies greatly with the age. In the foetus in utero, the pulsations vary from 140 to 150 in the minute; in the newly-born infant, from 130 to 140; in the 2d year, from 100 to 115; from the 7th to the 14th year, from 80 to 90; from the 14th to the 21st year, from 75 to 85; and from the 21st to the 60th year, 70 to 75. After this period, the pulse is generally supposed to fall in frequency, but the most opposite assertions have been made on this subject. There are many exceptions to the preceding statement; young persons being often met with having a pulse below 60, and cases not unfrequently occurring in which the pulse habitually reached 100, or did not exceed 40 in the minute, without apparent disease. The numbers which have been given are taken from an equal number of males and females, and the pulsations taken in the sitting position. The influence of sex is very considerable, especially in adult age, the pulse of the adult female exceeding in frequency that of the male of the same age by from 10 to 14 beats in the minute. The effect of muscular exertion in raising the pulse is well known; and it has been found by Dr Guy that posture materially influences the number of pulsations. Thus, in healthy males of the mean age of 27 years, the average frequency of the pulse was, when standing, 81, when sitting, 71, and when lying, 66, per minute; while in healthy females of the same age the averages werestanding, 91; sitting, 84; and lying, 79. During sleep, the pulse is usually considerably slower than in the waking state. In disease (acute hydrocephalus, for example), the pulse may reach 150 or even 200 beats; or, on the other hand (as in apoplexy and in certain organic affections of the heart), it may be as slow as between 30 and 20. Irregularity of the pulse is another condition requiring notice. There are two varieties of irregular pulse: in one, the motions of the artery are unequal in number and force, a few beats being from time to time more rapid and feeble than the rest; in the other variety, a pulsation is from time to time entirely left out, constituting intermission of the pulse. These varieties often concur in the same person, but they may exist independently of each other. Irregularity of the pulse is natural to some persons; in others, it is the mere result of debility; but it may be caused by the most serious disorders, as by disease of the brain, or by organic disease of the heart; and hence the practical importance of ascertaining the various meanings of this symptom. The pulse is said to be full when the volume of the pulsation is greater than usual, and it is called small or contracted under the opposite condition. A full pulse may depend upon general plethora, on a prolonged and forcible contraction of the left ventricle of the heart, and possibly, to a certain extent, on relaxation of the arterial coats; while a small pulse results from general deficiency of blood, from feeble action of the heart, from congestion of the venous system, or from exposure to the action of cold. When very small, it is termed thread-like. The tension of the pulse is the property by which it resists compression, and may be regarded as synonymous with hardness. A hard pulse can scarcely be stopped by any degree of pressure of the finger. It occurs in many forms of inflammation, and its presence is commonly regarded as one of the best indications of the necessity of venesection. A soft or compressible pulse is indicative of general weakness. For The strength of the pulse depends chiefly on the force with which the blood is driven from the heart, but partly also upon the tonicity of the artery itself and the volume of the blood. A strong pulse is correctly regarded as a sign of a vigorous state of the system; it may, however, arise from hypertrophy of the left ventricle of the heart, and remain as a persistent symptom even when the general powers are failing. As strength of the pulse usually indicates vigour, so weakness of the pulse indicates debility. There may, however, be cases in which weakness of the pulse may occur in association with undiminished energy of the system at large. example, active congestion of the lungs may so far impede the passage of the blood through these organs that it cannot reach the heart in due quantity; the necessary result is a weak and feeble pulse, which will rapidly increase in strength if the congestion is relieved by free blood-lettings. Various expressive adjectives have been attached to special conditions of the pulse, intc the consideration of which our space will not permit us to enter. Thus, we read of the jerking pulse, the hobbling pulse, the corded pulse, the wiry pulse, the thrilling pulse, the rebounding pulse, &c. PULTOWA. See POLTAVA. PU'LTUSK, a town of Poland, in the govern ment of Plock, is situated in a thickly-wooded district on the Narew, 35 miles north-north-east of Warsaw. It contains numerous churches and a very large bishop's palace. Pop. 4772. Here, on December 26, 1806, was fought one of the battles of the campaign of Eylau, between the Russians The field was most obstinately and the French. contested, but the victory, which, however, was claimed by both armies, inclined in favour of the French. PU'LU, a beautiful substance, resembling fine silk, of a rich brown cclour and satin lustre, used largely as a styptic by the medical practitioners of Holland, and lately introduced into this country for the same purpose. It consists of the fine hairs from the stipes of one or more species of tree-fern, referrible, without doubt, to the genus Cibotium. It was first imported into this country in 1844 from Owhyhee under the name of Pulu, or vegetable silk, and was proposed as a substitute for silk in the manufacture of hats, but could not be applied. In 1856, it was again imported from Singapore under the Malay names of Penghawar Djambi and Pakoe Kidang, and was said to have been used in Dutch pharmacy for a long period as a styptic. Several importations have since taken PUMA-PUMPS. place, and it has been successfully used. It acts action. Of these, as the most important, we shall mechanically by its great absorbent powers. describe in detail the following: 1. The Lift or PU'MA, or COUGAR (Felis concolor, Leopardus Suction Pump; 2. The Lift and Force Pump; 3. concolor, or Puma concolor), one of the largest of The Chain-pump; 4. The Centrifugal Pump; 5. the American Felidæ, rivalled only by the jaguar. The Jet-pump. It is sometimes called the American Lion, although 1. The Lift or Suction Pump.-The diagrams it is more allied to the leopard, notwithstanding figs. 1 and 2 represent the ordinary suction pump. its want of spots and stripes. It is from 4 to 4A is a cylinder, which is called the barrel; with it is feet in length from the nose to the root of the tail, connected at the bottom a pipe, B, which communiand the tail about 2 feet or 24. The fur is thick cates with the water to be raised; and at its top is and close, reddish-brown above, lighter on the sides, another pipe, C, which receives the water raised. and reddish-white on the belly; the muzzle, chin, In the barrel are placed two valves, D and E. D is throat, and insides of the legs grayish-white, the fixed in position at the bottom of the barrel; E is breast almost pure white. Young pumas have darkbrown spots in three rows on the back, and scattered markings elsewhere, exhibiting the relation to the leopards. The long tail of the P. is covered with thick fur, and is generally coiled up, as if it were prehensile, which it does not seem to be, although the P. climbs trees very well, and often descends on its prey from among their branches. The P. was formerly found in all except the coldest parts of America, but is now rare in most parts of North America, having been expelled by man. rarely attacks man, but is very ready to prey on domestic animals, and seems to have a thirst for blood beyond that of other Felida, one P. having been known to kill 50 sheep in a night, drinking a little of the blood of each; a very sufficient reason for the anxiety which all American farmers shew for its destruction. Yet it is easily tamed, and when tamed, a very gentle creature, purring like a cat, and shewing equal love of attentions. The geographical range of the P. extends far southwards in Patagonia, and northwards even to the state of New York, although it is now very rare in all long-settled parts of North America. the Painter (Panther) of North American farmers. It sometimes issues from the forests, and roams over prairies and pampas, and is not unfrequently caught by the lasso of South American hunters.A BLACK P. (Felis nigra of some naturalists), a doubtful species, and probably only a variety of the common P., is found in some parts of South America. It It is B Fig. 1. F D H The hollow PU'MICE, a mineral found in volcanic countries, generally with obsidian and porphyries. In chemical composition, it agrees with obsidian, of which attached to, and forms part of the piston F, which it may be regarded as a peculiar form, rapidly moves up and down the barrel when motive-power cooled from a melted and boiling state. It is of a is applied to the rod G. white or gray colour, more rarely yellow, brown, consists of a cylindrical piece of wood or metal, The piston, or bucket, or black; and so vesicular, that in mass, it is which fits exactly the barrel in which it moves, lighter than water, and swims in it. The vesicles, so that no water or air can pass between its circumor cells, are often of a much elongated shape. P. ference and the sides of the cylinder. This tight often exhibits more or less of a filamentous fitting is attained in wooden pistons by surrounding structure; and it is said to be most filamentous them with a leather ring; and in those of metal, by when silica is most abundant in its composition. hemp or other packing, which is wrapped round a It is very hard and very brittle. It is much made in their outer surface. groove used for polishing wood, ivory, metals, glass, slates, interior of the piston is closed at the top by the marble, lithographic stones, &c., and in the pre-valve E, which is a kind of door opening on a hinge, paration of vellum, parchment, and some kinds of at one side of it, in an upward direction, on the leather. Among other purposes to which it is applied is the rubbing away of corns and callosities. application of pressure, and shutting on to its seat Great quantities are exported from the Lipari Isles to Britain and all parts of Europe. The Lipari Isles are in great part composed of P., which there, as in some other places, occurs as a rock. P. is the chief product of some volcanic eruptions; but in some eruptions, none is produced. It is found also in regions where there are now no active volcanoes, as at Andernach on the Rhine. PUMPKIN. See GoUrd. PUMPS are machines for raising water and ather fluids to a higher level. They are divided into several classes according to their mode of on the piston when the pressure is removed. When opened, water or air can pass through it to the upper side of the piston; but when shut, none can pass from one side of the piston to the other. The other valve, D, is similar to it in all respects, except that, as before stated, it is fixed in the bottom of the barrel; it also can only open upwards. On To describe the action of the pump, we shall suppose the piston to be at the bottom of the barrel, and the pump to contain nothing but air. moving the piston up the barrel-the valve in it being shut, and kept so by the atmospheric pressure above it-no air can pass from above it into the PUMPS. part of the barrel from which it is moving; the air contained in which becoming rarefied, by having to occupy a greater space, exerts less pressure on the valve D at the bottom of the barrel than the air in suction-pipe B below it. This valve is thus opened, and the air from the suctionpipe enters the barrel; so that when the piston has arrived at the top, a volume of air equal to the contents of the barrel has passed from the suction-pipe into the barrel. When the piston descends, it compresses the air in the barrel, which shuts the valve D; and when the C density of the compressed air becomes greater than that of the atmosphere, the valve E in the piston is forced open, and the air in the barrel passes to the upper side of the piston. The next upward stroke of the piston again draws a like quantity of air from the suction-pipe into the barrel; and, as none of this air again enters the pipe, but is passed to the upper side of the piston by its downward stroke, the suction-pipe is by degrees emptied of the air it contained. During this process, however, motion has taken place in the water at the foot of the suction-pipe. The surface of the water at H is pressed upon by the weight of the atmosphere with a pressure of about 15 A E B Fig. 2. lbs on every square inch; and by the laws of fluidpressure, if an equal pressure is not exerted on the surface of the water in the suction-pipe, the water will rise in it, until the pressure on its surface, plus the weight of its fluid column, balances the pressure of the atmosphere on the surface H outside; so that, as the air in the suction-pipe is rarefied, the water rises in it, until, when all the air is extracted from it, the water stands at the level of the valve D. By the next upward stroke of the piston, the barrel being emptied of air, the water follows the piston, and fills the barrel as it filled the suction-pipe. The pressure produced by the downward stroke shuts the valve D, and forces the water in the barrel through the valve E. The succeeding upward stroke carries this water into the pipe above, and again fills the barrel from the suction-pipe. In like manner, every successive upward stroke discharges a body of water equal to the content of the barrel into the pipe above it, and the pump will draw water as long as the action of the piston is continued. The action of this pump may be more shortly described by saying that the piston withdraws the air from the barrel, and produces a vacuum, into which the water rushes through the suction-pipe, impelled by the pressure of the atmosphere on its surface. This atmospheric pressure balances a column of water of about 33 feet in height; so that if the barrel be placed at a greater height than this from the surface of the water in the well, the water will not rise into it, and the pump will not draw. With regard to its efficiency-that is to say, the relation between the power expended and the work produced, as measured by the water raised-we may remark, that the power is expended-1st, in raising the water through the required height; 2d, in overcoming the friction of the moving parts of the pump; 3d, in the friction and fluid resistance of the water in passing through the valves and pipes; 4th, in the losses arising from the want of proper proportion between the various parts of the pump. The losses arising from these last sources are very great, and vary so much according to the construction of each particular pump, that no useful estimate can be formed of the efficiency. We may say, however, that a pump of this description, to yield 50 per cent. of the applied power, must be well proportioned and carefully constructed. 2. The Lift and Force Pump.-Figs. 3 and 4 represent two varieties of this pump. That shewn in fig. 3 is very similar to the suction-pump before described, with this exception, that the valve E, instead of being fixed on the piston, is placed in the discharge-pipe, the piston itself being solid. The water is drawn up into the barrel by suction in the manner just described in the suction-pipe, and then the pressure of the piston in its downward-stroke forces it through the valve E to any height that may be required. That shewn in fig. 4 is provided with a different description of piston, called the plunger-pole. Its action is precisely the same as that of the other, with this exception, that the plunger-pole, instead of emptying the barrel at every stroke, merely drives out that quantity which it displaces by its volume. It is simply a solid rod of metal, A, moving through a water-tight stuffingbox, B. This stuffing-box is made by placing, on a circular flange of metal, rings of india-rubber or other packing, the inner diameter of which is slightly less than that of the plunger-pole. On these is placed a ring of metal, and through the whole are passed bolts, which, on being screwed tight, force the packing tightly against the plungerpole. It possesses many advantages, for the packing can be tightened and repaired without removal of the piston or stoppage of the pump; also, the cylinder is not worn by its action, nor does it require to be accurately bored out, as in the other form of pump. In these pumps, it will be observed that the water is forced into the ascending pipe or column only on the downward stroke; it will thus be PUMPS. sense, as a means of producing a given result with the least possible expense of power. In those exhi bited in the International Exhibition of 1862, we find a marked improvement. The jury report that a large number of constructers have sought to give the waterways and valves dimensions which render as small as possible the loss of power by friction. They have also sought to give a continuous movement to the ascending column of water, indepen dently of the action of the reservoir of air.' discharged in a series of rushes or jerks. As it is a great object to procure a continuous discharge, both for its convenience, and for the saving of the power wasted by the continual acceleration and retardation of the ascending column, various methods have been used for that purpose. The most common is the reservoir of air, which is an air-tight receptacle fixed vertically on the discharge-pipe; the water forced into the pipe by the down-stroke compresses this air, which, acting as a spring, returns this force to the ascending column during the period of the 3. The Chain-pump.-This pump is formed in up-stroke, and so, by taking the blow of the enter- general of plates of wood fastened to an endless iron ing water, and returning it gradually, equalises chain, and moving upwards in a rectangular case or the pressure, and renders box. Fig. 6 shews an example of this pump, which the discharge uniform. was exhibited in the International Exhibition of Another method is the 1862, called 'Murray's Chain-pump ;' a pump which double-action force-pump, is very much used on public works, on account of by which equal volumes of water are forced into the ascending column by both up and down strokes. An example of this is shewn in fig. 5. The solid piston A is worked by a rod B of half the section of the piston itself. During the up-stroke, the upper surface forces a volume of water into the ascending column, and the lower surface draws in twice that volume. In the down-stroke, these two volumes are sent through the pipe E into the receptacle C, communicating with the upper face of the piston. One of the volumes fills the space D, which would otherwise be left empty by the descent of the piston; the other volume is sent into the ascending column; so that a volume of water equal to half the content of the barrel is sent into the ascending column by both the up and the down strokes. E Fig. 5. B A pump exhibited in the International Exhibition of 1862, by Messrs Farcot and Sons, attains this object in a much more simple manner. In it 'two equal pistons, with valves affording very large water-ways, work parallel to each other in two pump cylinders. During the successive strokes, the first piston draws in water by its upper surface, and delivers it to the ascending column by causing it to traverse the second piston. In its ascending course, the second piston raises in its turn the column of water by its upper face, while the lower face sucks the water, causing it to traverse the first piston.' It will be seen from this description that a valve is placed in each piston, that the cylinders communicate at their base, and that the pistons make their strokes simultaneously. This pump has yielded all the good results promised by its ingenious construction, and it is adopted in the water-supply of Paris. In spite of the great antiquity of the lift and force pump, it is only of late years that improvements have been introduced into its construction capable of rendering it an efficient machine-that is, one which returns in the shape of water raised, a good proportion of the power applied to it. In 1849, M. Morin found by experiments that the power lost was 55 to 82 per cent.-that is to say, that of the motive-power, 45 per cent. was yielded in the best and 18 in the worst, giving an average of about 30 per cent. In 1851, the jury, reporting on those exhibited in the Great Exhibition, say that it is one of our worst machines, considered in a mechanical Fig. 6.-Murray's Chain-pump. the ease of its construction and erection, and its admirable efficiency even at considerable heights. In this pump, the friction is reduced by having only 3 or 4 lifts instead of 20 or 30, as was previously the case. The chains pass under a roller, A, at the foot, and are driven by a small pitch-wheel, B, at the top, over which they are conducted, and which is driven by appropriate gearing. The lifts feather in passing over the wheel to the descending side, and only unfold when brought round to the ascending side; thus the pump is enabled to take off the water with the same dip as other pumps. The pump is not liable to be choked, as a back turn of the chain immediately releases any substance getting between the lift and the barrel. The speed is variable, in proportion to the duty required. The speed at which the chain is ordinarily worked is from 200 to 300 feet per minute. The greatest lift yet made by Murray's chain-pump is 60 feet high; but it is considered that 100 tons of water per minute could be raised 100 feet high. From 10 to 12 feet apart has been found to be the best pitch for the lifts; putting |