In drawing deductions from national statistics, it must be borne in mind that, although national registration of births and deaths was inaugurated in 1837, that it became compulsory for medical practitioners to give certificates of the cause of death of each patient dying under their care. In children, the term broncho-pneumonia not infrequently conceals acute tuberculosis, especially when the broncho-pneumonia occurs after imperfect recovery from such diseases as whooping-cough and measles. This chapter discusses confusion between phthisis and other respiratory diseases. The most likely sources of error in phthisis statistics are deaths returned under the headings of bronchitis and pneumonia. In England and Wales, half of the 4315 deaths from general tuberculosis were transferred to phthisis, the phthisis death-rate would only be changed from 1.24 to 1.30 per 1000 of population. Tuberculous meningitis is nearly always secondary to other tuberculous diseases, as of the glands or joints.