Part 75

Capillary glass tubes are either cylindrical or furnished with a bulbous expansion at the middle, the latter form being most commonly used. To charge a tube make sure that both ends are open, and then submerge one end in the pool of lymph. Capillary attraction will cause the tube to fill, and the process may be facilitated materially by inclining the tube toward a horizontal direction, so that the capillary attraction is not opposed by that of gravitation. Care should be taken to keep the applied end of the tube constantly submerged, or bubbles of air will enter it. The sealing may be done with a blowpipe, by simply holding the ends in a flame, or by means of sealing-wax or some similar substance. The satisfactory charging of tubes demands some practice, but a little patience will enable any intelligent person to succeed.

In regard to crusts, they should never be removed until the surface beneath has become cicatrized and they have been partially detached by the natural process. A crust torn off prematurely should never be used, {480} and the same may be said of secondary crusts--i.e. those that form by the desiccation of the discharge from the raw surface left when the primary crust has been removed forcibly.

For the preservation of vaccine in these various forms tubes need only be kept in a cool place. Dried lymph and crusts should be guarded against dampness even more than against warmth. Their preservation may be decidedly favored by over-drying, either in an exhausted receiver or by keeping them in a closed vessel in the presence of sulphuric acid, chloride of calcium, or some other substance having a strong affinity for water. It is needless to say, however, that they should not come into actual contact with any such agent. While this artificial desiccation tends powerfully to preserve dried lymph, it makes it more difficult to use. When dried lymph or a crust is to be sent by mail or other conveyance, it should be wrapped in some impermeably envelope, for which purpose gutta-percha tissue is very convenient. Both these forms of virus should be kept in a cool place. There is no objection to keeping them on ice, provided they are well protected against moisture.

* * * * *

In conclusion, the writer wishes to say that the limited space at his command has compelled the assumption of a dogmatic rather than an inductive form in the construction of this article. To the reader who may wish to pursue the subject further--and it will well repay thorough study--he would recommend the following bibliography:

Ballard: On Vaccination: its Value and Alleged Dangers, London, 1868.

Bousquet: Nouveau traité de la vaccine et des éruptions varioleuses, Paris, 1848.

Bryce: Practical Observations on the Inoculation of Cow-pox, Edinburgh, 1809.

Ceely: Observations on the Variolæ Vaccinæ, Worcester, 1840.

Chauveau et al.: Vaccine et Variole, Paris, 1865.

Depaul: Nouvelles recherches sur la véritable origine du virus vaccin, Paris, 1863; De l'origine réelle du virus vaccin, Paris, 1864; et al.: De la syphilis vaccinale, Paris, 1865.

Hardaway: Essentials of Vaccination, Chicago, 1882.

Hering: Ueber Kuhpocken an Kühen, Stuttgart, 1839.

Jenner: An Inquiry, etc., 2d ed., London, 1800.

Sacco: Trattato di Vaccinazione, Milano, 1809.

Seaton: A Handbook of Vaccination, London, 1868.

Steinbrenner: Traité sur la vaccine, Paris, 1846.

{481}

VARICELLA.

BY JAMES NEVINS HYDE, M.D.

Varicella is an acute disorder of infancy and childhood, in the course of which appears a cutaneous exanthem of vesicular type, accompanied at times by systemic symptoms of moderate severity, terminating in the course of from three days to a fortnight, after the formation of relatively few crusts upon the skin, with occasionally persistent cicatrices.

SYNONYMS.--Eng., Chicken-pox; Ger., Windblattern, Schafpocken; Fr., Varicelle; Lat., Variola notha, seu spuria; Ital., Morviglione.

HISTORY.--The literature of the disease which is now best recognized under the title of varicella has been, in the history of medicine, wellnigh inextricably confused with that of variola. In the latter part of the seventeenth and the early part of the eighteenth century the distinction between typical forms of the two disorders became apparent, and was described by Willan and Harvey in England, and other writers in Germany, France, Holland, and Belgium. Among those who have contributed to its literature may be named Hebra, Kaposi, Trousseau, Simon, Thomas, Güntz, Henoch, Kassowitz, and Boeck.

ETIOLOGY.--Varicella is essentially a disease of early life, occurring almost exclusively in infants and young children. It is a contagious disorder, and at times, especially in hospitals and asylums for children, occurs in apparently epidemic forms. The question relating to the inoculability of the contents of its vesicular lesions is still open, positive and negative results being recorded by different experiments.

My personal view may be briefly formulated as follows: Practically and clinically, it is useful to regard these disorders as of a distinct nature. The arguments, however, in favor of such absolute distinction are not irrefutable. There is probably in both forms of disease but a single virus, that of variola; but this, modified by evolution among generations of vaccinated children, has, in this process of natural cultivation or attenuation, produced a malady of tender years whose attacks do not protect from variola and occur irrespective of vaccination.]

SYMPTOMATOLOGY.--The period of incubation of the disease cannot be said to be definitely established. At times, without question, an entire fortnight elapses between the dates of exposure and the evolution of the disease, but both longer and shorter intervals have been recorded.

{482} If there be a prodromal stage of the disease, certainly in the vast majority of the little patients it cannot be recognized. During the last month the writer has observed the evolution of the disease in twenty children gathered together in the Chicago Home for the Friendless, no one of whom was recognized as ailing before the eruption appeared. Occasionally the disease is preceded by mild or even severe febrile symptoms, accidents sufficiently common in this class of patients.

The exanthem, commonly the first symptom of the disorder, occurs in the form of reddish puncta, from which rapidly develop rosy-colored maculations, and these become tensely distended, transparent or slightly yellowish vesicles, of the average size of a split pea, though they are occasionally smaller or may enlarge to the dimensions of a bean or small nut. The eruption appears first upon the upper segment of the body, implicating the chest in front and behind, the neck, the scalp, particularly the extremities, and quite sparingly the face also, which may, however, entirely escape. In cases where the eruption is profuse it may be completely generalized, involving largely the trunk and extremities, the lesions, upon the back particularly, being as closely set together as in discrete variola. In many, even the majority, of cases the exanthem is much less profusely developed, not more than a dozen or twenty vesicles springing from the surface.