(_b_) In poisoning by salicylates. (_c_) In starvation, for obvious reasons. The supply of sugar from the liver has been used up, and the patient, living on his own fats, breaks them up abnormally. (_d_) In post-anæsthetic poisoning, for reasons which are at present not clearly ascertained. Upon the theoretical side it is therefore not possible to say more than that anæsthetics sometimes initiate this abnormal metabolic process. To the question as to why and how they do so, we can as yet give no answer. Upon the practical side, we can, however, speak much more definitely. Acidosis follows the use of ether very rarely indeed: after nitrous oxide it is unknown. Chloroform has been the drug used in almost every recorded case, while ethyl chloride has been responsible in a few isolated instances. Young children are much more prone to suffer than adults, though the author had a fatal case in a lady well over forty years of age: he has also seen a case very nearly fatal in a soldier aged twenty. This man was, a week after recovery from acidosis, anæsthetised for half-an-hour with nitrous oxide and oxygen, without exhibiting any signs of a return of his dangerous condition. Anæsthesia repeated in the same subject after a short interval is more prone to start the process than a first inhalation. Lastly, acute sepsis, particularly in the young, is notorious for its liability to be followed by acidosis. PREVENTION AND TREATMENT. The obvious moral of the foregoing is that chloroform should not be administered to patients suffering from acute sepsis, particularly if they be very young. Indeed, so common is a mild degree of acidosis among children, some surgeons consider there is a definite risk in giving chloroform to them at all unless special precautions are taken. Chief among these are regular dosage for a day or two before operation, with considerable doses of bicarbonate of soda and sugar, which is a routine measure in some children’s hospitals. As regards curative treatment, much can be done if the gravity of the condition is recognised early. The stomach is first washed out with alkalis, and a substantial dose (one dram) of bicarbonate of soda left in it. The same dose is repeated hourly by the mouth, if retained, or per rectum. A useful addition to the alkaline treatment is dextrose, also in teaspoonful doses. In grave cases, these drugs should be given intravenously in saline solution. These measures combined with warmth, and ample fluids by mouth or rectum, will often save life, but to be of any value they must be begun early. Fulminating cases occur which succumb rapidly in spite of treatment. CHAPTER XVIII. POSTURE OF THE PATIENT.