When Scarlet Fever is complicated--as it sometimes is--with diphtheria, the diphtheric membrane is very apt to travel into the wind-pipe, and thus to cause diphtheric croup, it is almost sure, when such is the case, to end in death. When a child dies from such a complication, the death might truly be said to be owing to the diphtheric croup, and not to the Scarlet Fever, for if the diphtheric croup had not occurred, the child would, in all probability, have been saved. The deaths from diphtheria are generally from diphtheric croup, if there be no croup, there is, as a rule, frequent recovery. 220. _How would you distinguish between Scarlet Fever and Measles_? Measles commences with symptoms of a common cold, scarlet fever does not. Measles has a _peculiar hoarse_ cough, scarlet fever has not. The eruption of measles is in patches of a half moon shape, and is slightly raised above the skin, the eruption of scarlet fever is _not_ raised above the skin at all, and is one continued mass. The colour of the eruption is much more vivid in scarlet fever than in measles. The chest is the part principally affected in measles, and the throat in scarlet fever. There is an excellent method of determining, for a certainty, whether the eruption be that of scarlatina or otherwise. I myself have, in several instances, ascertained the truth of it--"For several years M Bouchut has remarked in the eruptions of scarlatina a curious phenomenon, which serves to distinguish this eruption from that of measles, erythema, erysipelas &c., a phenomenon essentially vital, and which is connected with the excessive contractability of the capillaries. The phenomenon in question is a _white line_, which can be produced at pleasure by drawing the back of the nail along the skin where the eruption, is situated. On drawing the nail, or the extremity of a hard body (such as a pen-holder), along the eruption, the skin is observed to grow pale, and to present a white trace, which remains for one or two minutes, or longer, and then disappears. In this way the diagnosis of the disease may be very distinctly written on the skin; the word 'Scarlatina' disappears as the eruption regains its uniform tint."--_Edinburgh Medical Journal._ 221. _Is it of so much importance, then, to distinguish between Scarlet fever and Measles_? It is of great importance, as in measles the patient ought to be kept _moderately_ warm, and the drinks should be given with the chill off; while in scarlet fever the patient ought to be kept cool--indeed, for the first few days, _cold_--and the beverages, such as spring-water, toast and water, &c., should be administered quite cold. 222. _Do you believe in "Hybrid" Scarlet Fever--that is to say, in a cross between Scarlet Fever and Measles_?