Notwithstanding this singular usage of the vocabularies and dictionaries, the name of smallpox occurs by itself in letters or other memorials of the Elizabethan period, having been doubtless correctly applied to the true pustular variola. In the short essay on smallpox by Kellwaye, appended to his book on the plague (1593), measles and smallpox are distinguished on the whole clearly, according to the definitions of Fracastori or other foreign writers of the 16th century. The association between measles and smallpox that survived longest was a peculiar and somewhat uncommon one; certain cases of smallpox, in which the pustules were wholly or partially represented by, or changed into, broad spots level with the skin, red or livid in colour, and in which haemorrhages occurred from the nose, lungs, bowels or kidneys, that is to say, cases of haemorrhagic smallpox, were apt to be called, from the time of James I. until as late as the case of Queen Mary in 1694, by the name of “smallpox and measles mingled.”
From the date of the annual bills of mortality by the Parish Clerks of London, the year 1629, it is improbable that there was any real confusion between smallpox and measles; there was certainly some ambiguity in the entry of measles long after, but that later confusion, especially in the second half of the 18th century, was with scarlatina[1184]. The entry of measles is in the bills from the first, apart from that of “flox and smallpox:”
| Year | Measles deaths | Smallpox deaths | ||
| 1629 | 42 | 72 | ||
| 1630 | 2 | 40 | ||
| 1631 | 3 | 58 | ||
| 1632 | 80 | 531 | ||
| 1633 | 21 | 72 | ||
| 1634 | 33 | 1354 | ||
| 1635 | 27 | 293 | ||
| 1636 | 12 | 127 | ||
| 1647 | 5 | 139 | ||
| 1648 | 92 | 401 | ||
| 1649 | 3 | 1190 | ||
| 1650 | 33 | 184 | ||
| 1651 | 33 | 525 | ||
| 1652 | 62 | 1279 | ||
| 1653 | 8 | 139 | ||
| 1654 | 52 | 832 | ||
| 1655 | 11 | 1294 | ||
| 1656 | 153 | 823 | ||
| 1657 | 15 | 835 | ||
| 1658 | 80 | 409 | ||
| 1659 | 6 | 1523 | ||
| 1660 | 74 | 354 |
In the great epidemic of smallpox in 1628, the year before the bills begin, Thomas Alured wrote to Sir John Coke that his house in London had been visited “once with the measles and twice with the smallpox, though I thank God we are now free; and I know not how many households have run the same hazard[1185].” In the year 1656, which has the highest total in the above table, two cases of measles are mentioned in a letter of 31st May: “Young Sir Charles Sedley is at this time very sick of a feaver and the meazells, of which Sir William dyed”—Charles Sedley being then in his seventeenth year[1186]. An instance parallel to that of 1628, of measles and smallpox co-existing in the same household, occurred in the royal palace at Whitehall in December, 1660. The princess of Orange, sister of the king, died of smallpox on the 23rd; on that day, or a day or two before, her sister the princess Henrietta, who had come from France on a visit with the queen-mother, Henrietta Maria, removed from Whitehall to St James’s, “for fear of infection.” After a few days she embarked on board the ‘London’ at Portsmouth to return to France, but the ship had to come to anchor again owing to the princess being attacked with “the measles.” Her illness, which delayed the sailing of the vessel until the 24th of January, 1661, is uniformly spoken of as the measles in the various letters which make mention of it[1187]. In that year, and in several of the next ten years, the measles deaths in London reached a considerable total:
| Year | Measles deaths | |
| 1661 | 188 | |
| 1662 | 20 | |
| 1663 | 42 | |
| 1664 | 311 | |
| 1665 | 7 | |
| 1666 | 3 | |
| 1667 | 83 | |
| 1668 | 200 | |
| 1669 | 15 | |
| 1670 | 295 |
The epidemic of 1670 is the subject of a description by Sydenham, the diagnostic points of which were doubtless those current at the time.
Sydenham’s description of Measles in London, 1670 and 1674.
Sydenham’s account of the epidemic of 1670 is full enough to leave no doubt that it was measles of the ordinary kind; the details, indeed, are as minute for all essential points as they would be in a modern text-book[1188]:
Measles, he says, is a disease mainly of young children (infantes), and is apt to run through all that are under one roof. It begins with a rigor, followed by heats and chills during the first day. On the second day there is fever, with intense malaise, thirst, loss of appetite, white tongue (not actually dry), slight cough, heaviness of the head and eyes, and constant drowsiness. In most cases a humour distils from the nose and eyes, the effusion or suffusion of tears being the most certain sign of sickening for measles, more certain indeed than the exanthem. The child sneezes as if it had taken cold, the eyelids swell, there may be vomiting, more usually there are loose green stools (especially during dentition), and there is excessive fretfulness. On the fourth or fifth day small red maculae, like fleabites, begin to appear on the forehead and the rest of the face, which coalesce, as they continue to come out in increasing numbers, so as to form racemose clusters. These maculae will be found by the touch to be slightly elevated, although they seem level to the eye. On the trunk and limbs, to which they gradually extend, they are not elevated. About the sixth day the maculae begin to roughen and scale, from the face downwards, and by the eighth day are scarcely discernible anywhere. On the ninth day the whole body is as if dusted with bran. The common people say that the spots had “turned inwards,” by which they mean that, if it had been smallpox, they would have remained out longer, and have proceeded to suppuration or maturation. The rash having thus “gone in,” there is an access of fever, attended with laboured breathing and cough, the latter being so incessant as to keep the children from sleep day or night. If they had been treated by the heating regimen, they are apt to have the chest troubles pass into peripneumonia, by which complication measles becomes more destructive than smallpox itself, although there is no danger in it if it be rightly treated. When peripneumonia threatens, the patient should be bled, even if it be a tender infant. Diarrhoea, which sometimes continues for weeks after an attack of measles, may be cut short by blood-letting, and so also may whooping-cough.
This epidemic, says Sydenham, began in January, and was almost ended in July, which agrees exactly with the rise and decline of measles deaths in the weekly bills of the Parish Clerks.