of connecting the standard types of mixed nations with the races composing them. The stature curve of England differs visibly in proportions from that of Italy, the measurements of Scotch and American soldiers show very different mean and extreme terms, and the problems of race underlying these differences are of a most complex character, the more so when the consideration is introduced of the race type varying within itself from century to century. M. Quetelet is naturally apt, when expressing his views in an exordium or a peroration, to draw a good deal on the anticipated future results of his admirable method; but in judging of the value of his doctrine of central types, the best criterion is his actual success in reducing the observed facts of Nature to numerical calculation. The future must show how far it will be possible to apply to the theory of species the definition of central specific forms, from which varieties calculably diminish in numbers as they depart in type.—Nature.
| DISINFECTION AND DISINFECTANTS. |
By WILLIAM EASSIE, C. E.
THERE are certain rules to be promulgated respecting the protection of human life from contagion, or from the injurious effects of decomposing organic matters, which may be gleaned from the experience of ages, and which as yet have never been laid down with sufficient clearness.
A writer in a medical journal, the other day, pointed out, from the "Odyssey" of Homer, the great solicitude of Ulysses for the purification of his house with sulphur, and the history of purgation could go still farther back, and bring to light many other interesting memorabilia. This, however, hardly comes within the scope of these short papers; neither, as I said before, would any attempt to explain the cause of disease, for it would only be a repetition of wise things said before. Happily, too, the grim dwellers of the threshold are now watched with eye of lynx and nerve of steel, and their newer thrusts at poor mankind met or parried. Names like those of Drs. Parkes and Sanderson, in this respect, are fast becoming household words. For the purposes of this chapter, however, I cannot forbear from condensing the remarks of Dr. Angus Smith, with respect to disease generally. According to this authority, the classes of disease may be caused—firstly, by gases easily diffused in air, such as carbonic acid, nitrogen, marsh gas, and others; secondly, by vapors falling in cold air and taken up in fogs, volatile bodies in fact, that concentrate in cool temperatures, and not to be classed with gases; thirdly, by putrid or decomposing substances,
