581 



CANTHARIS OFFICINALIS. 



CANTONMENTS. 



582 



The volatile principle which is exhaled by the living insect is so pun- 

 gent as to cause gjeat inconvenience to those who approach the trees 

 where they alight. They are generally collected during the morning 

 or evening when somewhat torpid, by persons, whose face and hands 

 are protected by coverings, shaking or beating with poles the trees on 

 which the insects are seated. The most common method of killing 

 them is to expose them to the vapour of hot vinegar ; they are then 

 dried on hurdles, and put up for use. Turpentine is said to protect 

 them from the attacks of certain small insects, which prey upon par- 

 ticular parts of the dead insects. These insects are, a inite (Aearus 

 '"MS), a moth (Tinea ftarifronttUa), and two very small beetles 

 (Anthrenu* mtunrttm and Hofilia farinosa). 



The common blistering fly is sometimes foiind in Suffolk and Essex. 

 Though bearing the name of Spanish blistering flies, the greatest 

 quantity is obtained from St. Petersburg ; and the Russian insects are 

 superior to those from Sicily or France. When good, they are of a 

 shining yellowish-green colour ; the odour is strong, virose, disagree- 

 able, resembling that of mice ; taste acrid, caustic, urinous. By drying 

 they lose a great portion of their weight ; but age does not greatly 

 lessen their active properties if preserved from damp. The worms or 

 insects which attack them feed only on the inert part, and are only so 

 far injurious that they create a quantity of dust which is not vesicant ; 

 consequently, where worms are present in large proportion, more of 

 the powder must be employed. 



Cantharides, analysed by Robiquet, yielded : 



1. A green, fluid oil, insoluble in water, but soluble in alcohol 

 (inert). 



2. A black matter, soluble in water, but not in alcohol (inert). 



8. A yellow viscid matter, soluble in water, and in alcohol at the 

 common temperature ; which has no vesicating power. 



4. A white substance, under the form of small crystalline plates ; 

 when pure, insoluble in water ; but soluble in that liquid when mixed 

 with the yellow matter ; soluble in boiling alcohol, from which it is 

 deposited on cooling in crystalline plates ; it is also soluble in fixed 

 oils. To this principle the name of canthnradin has been given ; many 

 consider it a kind of animal camphor. It is the vesicating principle of 

 the insect. [CANTHARiDra.] 



5. Another fatty matter, insoluble in alcohol (inert). 



6. Phosphate of lime ) . , 



7. magnesia { "> the skeleton. 



8. A small portion of free acetic acid. 



9. A still larger portion of free uric acid. 



Possibly other principles exist in them. The odour is due to a 

 Tolatile oil, which is very pungent, and when it reaches the eyes causes 

 gevere ophthalmia. 



Cantharidin may be extracted in various ways; but where it is 

 desired for practical purposes to employ cantharidin apart from the 

 other constituents of the fly, turpentine, at the temperature of 212 

 Fahr., allowed to stand upon a number of the powdered flies, especially 

 the large female flics, will extract it ; and the terebinthinate solution 

 may be used as a most efficacious vesicant. Cantharidin is so 

 powerful, that one-hundredth part of a grain applied to the skin 

 will excite vesication. Cantharides are employed both externally 

 and internally ; but even when applied externally, should their 

 active principles be absorbed, the same effect will be produced 

 as if taken by the mouth. Applied to the skin, in moderate 

 quantity, the only effect is rubefaction of the part, followed in general 

 by vesicles or blisters, and the secondary effects of counter-irritants on 

 the system at large. Should any of it be absorbed, a specific effect 

 will be exerted on the urino-genital organs, precisely as if administered 

 by the mouth. If a very large quantity be absorbed or introduced 

 into the system by the mouth, or any other channel, such as injection 

 by a vein, a powerful and often dangerous degree of action is exerted 

 on the cerebro-spinal system, giving rise to violent nervous symptoms. 

 The quantity which acts as a poisonous dose varies greatly in different 

 individuals. This difference of degree of action is referable to idio- 

 syncrasy ; and while one individual has been sensibly affected by 

 merely smelling the powder, six ounces of the tincture have been 

 taken by another without injury. It is a medicine which requires the 

 utmost circumspection in its administration. Even the process of 

 powdering it should be carried on in such a way as to secure the 

 operator from either inhaling any of the floating particles, or from 

 receiving the volatile principle in his eyes. For internal adminis- 

 tration, a solution in alcohol or ether is preferable to the powder, as it 

 can be more perfectly incorporated with any fluid vehicle, and pre- 

 vented from remaining in contact with the mouth or palate. The 

 cues in which its internal exhibition is necessary or justifiable are 

 very few. In some cases of atony of the bladder its use may be 

 allowed ; but it is productive of no benefit in diabetes, and should be 

 avoided. Externally cantharidcs in.iy be employed in various forms 

 for different purposes, to act as a local stimulant, to cause rubefaction, 

 to produce vesicles and a discharge of fluid, or simply for their 

 secondary effect*, which may be either stimulant or sedative, according 

 to circumstances. As a local stimulant, tincture of Cantharides is very 

 useful in the languid circulation of the extremities which leads to the 

 formation of chilblains. Cantharides appear to act primarily on the 

 nerves of the part to which they are applied, and afterwards on the 

 vessels. In certain conditions of the nervous system, such as occur in 



apoplexy and palsy, they do not cause vesicles to arise. To produce a 

 rubefacient action, either a mixture of the tincture with some olea- 

 ginous fluid may be applied, or the common blistering plaster may be 

 laid upon the part, and both removed before vesication has occurred. 

 This limited application of so potent an agent is often useful, and in 

 some instances all that can with safety be employed. In the inflam- 

 matory complaints of young children or feeble persons, it is necessary 

 to remove the applied substance before vesicles form, otherwise trouble- 

 some ulcers and occasionally gangrene ensue ; this is particularly apt 

 to follow when measles have preceded the application of a blister. 

 Sometimes the discharge of the serum is as exhausting as blood-letting, 

 and must be avoided by the above precaution. To quiet the irritability 

 of the nervous system of old people, accompanied with restlessness, 

 fidgettiness, and discontent, nothing is more effectual than this limited 

 application of Cantharides to the nape of the neck. In many chronic 

 cutaneous diseases, especially of the squamous or scaly, and even of the 

 pustular kind, the repeated application of blisters kept on only for a 

 short period is very advantageous. Nothing will so soon cure (along 

 with proper internal treatment, and attention to diet and regimen) 

 ring-worm of the scalp, as blisters applied alternately with poultices, 

 followed by creosote, so soon as the inflammatory stage is removed. 

 As a general rule, blisters, or the employment of Cantharides in any 

 way, are not proper at the commencement of any inflammatory com- 

 plaint. But after the stage of great vascular excitement is over, and 

 when a failure of the vessels of the parts is likely to take place, blisters 

 are of unquestionable service. Also when diseases are assuming the 

 chronic form, blisters have great power in preventing this, or removing 

 it when it has actually occurred. In deep-seated diseases of the joints 

 or bones, the frequent repetition of small blisters in the neighbourhood 

 of the part is of much utility. They are also of great use in relieving 

 pain of the chest in the latter stages of phthisis pulnionalis. 



In case of an over-dose, it is more easy to say what should not, than 

 to say what should be done. If vomiting has begun, it should be 

 encouraged, and should be caused where it has not commended, in 

 order to remove the substance from the stomach ; but the stomach- 

 pump is inadmissible, owing to the state of the throat and pharynx. 

 Oily fluids are condemned by some, who affirm that even warm water 

 is bad. Venesection may be necessary ; but the state of the nervous 

 system is to be kept in view, and the excitement, if any, moderated, or 

 if there be lethargy, the person is to be roused. Camphor is of little 

 use in allaying the strangury, haematuria, and other signs of over- 

 action of the kidneys : opiate enemata are most useful against these 

 symptoms. 



Several other insects contain cantharidiu, such as the Meloe proscara- 

 bftus, the Myldbris cichorii, the Coccinelia septemjiunctata, &c. These 

 or others are used in different parts of the world to produce vesica- 

 tions, especially the Cantharis ritatta, or potato-fly, and C.atmta, both 

 in North America ; 0. ruficcps, in Sumatra and Java ; C. ffir/as and O. 

 i-iolacca, in the East Indies ; C. atomaria, in the Brazils ; C. Syriaca, in 

 Arabia ; Meloe majalis, M. proscambaus, and Myiabris cichorii, in 

 China and East Indies, also Myiabris trianthemre ; M. pustulala, Cape of 

 Good Hope, used in China ; Lydus trimaculatus, in the north of Europe. 

 The old crude method of applying blistering plaster made of the 

 powdered flies is almost entirely exploded. A small portion of linen 

 cloth cut the size and shape of the blister desired is to be dipped in 

 the acetous or terebinthinate solution of Cantharides and applied to the 

 spot. Or the portable and clean vesicating paper, or blistering tissue 

 paper are preferable. Chloroform is a good solvent for cantharidin. 

 Very improper uses are occasionally made of Cantharides, from which 

 serious injury may result. These are sometimes given or taken from 

 ignorance, but more frequently with a criminal object. Cantharides is 

 an ingredient in a preparation of iron or steel, where its presence is not 

 suspected. Common iron or steel lozenges are safe enough where any 

 preparation of iron is required, but the aromatic lozenges of steel con- 

 tain, besides sulphate of iron, tincture of Cantharides the prolonged 

 or injudicious use of which may have an injurious effect on the kidneys, 

 bladder, &c., not to mention the nervous symptoms Cantharides can 

 produce. These nervous symptoms do not always appear immediately ; 

 sometimes not for a week or a fortnight, when their cause may not be 

 remembered or suspected. 



CANTICLES. [SOLOMON, THE SONG OF.] 



CANTILEVER, a bracket with a projection beyond the line of the 

 supporting wall, considerably in excess of the width of its face. The 

 name is applied utterly irrespective of the nature of the material 

 of which the cantilever is composed. The strength of a cantilever is 

 to be ascertained by considering it as a beam loaded at one end, and 

 having one solid bearing, unless the section should be such as to render 

 it equivalent to a beam supported also by an inclined strut. 

 CANTO FERMO. [PLAIN CHANT.] 

 CANTON'S PHOSPHORUS. [CALCIUM, SULI-HIDE OF.] 

 CANTONMENTS are the dwelling-places occupied by an army 

 during any suspension of active operations in the field [TACTICS] : the 

 term, though frequently applied to winter-quarters, particularly desig- 

 nates the more temporary shelter which an army may occasionally 

 take ; for example, during a season of excessive heat. The troops are 

 distributed in villages, houses, &c., as when in winter-quarters, but 

 they are made to occupy a smaller extent of country, and hold them- 

 selves in readiness to take the field at a moment's warning. 



