4 Ibid., Oct., 1868, p. 333.
5 Würzbr. Verh., N. F., v., 1874, quoted by Forchheimer in Supplement to Ziemssen's Cyclopedia, W. T., 1881, p. 102.
Braidwood and Vacher,6 as the result of a number of experiments, believed that they had sufficient evidence for concluding that the most active mode of the transmission of measles was through the breath, and accordingly instituted a series of experiments by carefully examining the breath of children in the acute stage of the disease.7 With this object in view they coated over with glycerine the inside of several clean glass tubes of a diameter of a half to three-quarters of an inch. As soon as the nature of the eruption was manifest the patient was required to breathe through one or more of the tubes, and so on each day till the eruption had faded. Upon examination of the glycerine with an one-eighth objective every specimen showed numerous sparkling bodies, something like those found in vaccine, but larger. Some were spherical; others were elongated, with sharpened ends. They were most abundant during the first and second days of the eruption. Healthy children and patients suffering from typhoid and scarlet fevers were made to imitate these experiments, but no such bodies were to be seen in their specimens. They conclude from these observations that the small spherical elements discovered in the breath are perhaps the active agents in the propagation of measles. Upon post-mortem of patients who had died of rubeola these germs were found in the lungs and liver, and, particularly, close to the walls of the capillaries. They believe that the "lungs are the favorite breeding-ground of the contagium."
6 Brit. Med. Jour., Jan. 21, 1882.
7 Several years ago Ransome of Manchester obtained particles from the breath of two persons suffering from measles (Squire).
That inoculation of morbillous blood may convey the disease was first demonstrated by Home in 1757, which experiments were verified by Speranza in 1822 and by Katona in 1842. The inoculations of the latter are especially noteworthy, as they numbered more than a thousand. No person inoculated by him died, and only 7 per cent. of the inoculations failed. On the other hand, inoculations made by Mayr gave negative results. It is stated that Monro and Locke communicated measles by inoculating with the tears and saliva. Attempts of the same kind were fruitlessly made in Philadelphia in 1801, although the blood, the tears, the nasal and bronchial mucus, and the exfoliated lamellæ of the epidermis were successively employed in the trials.8
8 Rayer, Diseases of the Skin, Phila., 1845.
Mayr has shown that the nasal mucus is capable upon inoculation of propagating the disease. He performed the experiment upon two healthy children living at a distance from each other, at a time when the disease had ceased to be epidemic. Some nasal mucus taken from the patient during the stadium flavitionis, and kept fluid in a glass tube, was the same day placed upon the mucous membrane of each of these children. In one of them the first symptom of sneezing occurred after eight days, in the other at the expiration of nine days. Febrile symptoms set in two days later. In each child the rash appeared on the thirteenth day after infection. The inoculated disease was mild and regular in its course.
While it is perhaps true that the contagion of measles is not so tenacious as that of small-pox and scarlatina, it is a matter of observation that susceptible persons are liable to contract the disease, even if not directly exposed to its influence. There is incontestable evidence that it is conveyed by fomites—a fact well worth bearing in mind.
It is but just to say that so excellent an observer as Mayr taught that measles could not be conveyed by clothes, linen, etc. unless transferred immediately from one individual to another. Panum, however, showed that contagion could be carried many miles by an unaffected third person without losing its activity. Aitken9 has also pointed out the fact that children's clothes sent home in boxes from schools where the disease has raged communicated the disease, and that susceptible children who had slept in the same beds, in the same rooms, after they had been occupied by persons suffering from measles, have taken the malady. Squire observes that the contagium of measles, except in the catarrhal stage, is not far diffusible in the air, but clings to surfaces, and may be thus carried from place to place; on the other hand, children have been brought, while in full eruption, into a house among others, and nursed in a room apart, without any extension of the disease to the most susceptible.