FIELD AMBULANCES.

The medical unit lying next behind a regimental aid post is one of those whose functions, though not necessarily their organization, have been considerably augmented or otherwise varied since the war began, in accordance with local requirements.

Originally its main duty was to relieve of their sick and wounded the regimental aid posts, helping them also to clear the field at nightfall or whenever there was a pause in the battle, and treating the cases until it was possible to send them to treatment centres well away from the front. It had to serve in this way simultaneously three or four battalions, all presumed to be in action on an extended front, and the better to fit it for this work a field ambulance was made divisible into three sections, each capable of acting independently, and each again divisible into a stretcher-bearer subdivision for collecting the wounded and a tent subdivision for treatment of the patients.

In several of the localities in which the British army has been fighting during the last three years field ambulances have, no doubt, been working on this plan, but in France the conditions have necessitated a modification of their work and also to some extent of their constitution.

Each remains divisible as before, and each still possesses ten vehicles for the conveyance of wounded but seven of these are now motor ambulance cars, replacing seven horse- drawn ambulance wagons, and of the nine original medical officers one has been withdrawn. Furthermore, though every A.D.M.S. (senior officer of a division) still has three field ambulances under his direct command for the work of his division, and each of these retains its capacity to work as an independent unit, lie sometimes combines forces with the A.D.M.S. of another division, or the field ambulances of all the divisions of an army corps are in effect massed.

The duties they collectively perform are now practically as follows:

1. To collect the sick and wounded from battalions, whether these be actually fighting, serving as supports, or temporarily resting out of the line.

2. To decide what cases must be evacuated, and what shall be treated at the front.

3. To provide permanent treatment for those who fail to pass through the filter thus established, and for the rest temporary treatment pending evacuation.

4. To pursue a like course in respect of local sick, that is to say, cases of illness or injury arising amongst the large number of men who never but whose presence just in the rear of tile fighting line is essential to military operations.

5. To provide for the cleansing at frequent intervals of the persons of the men, the ridding of their clothes from vermin, and their disinfection when epidemic disease is in question.

6. To fill any gaps in the medical establishments of regiments, and to train medical officers and men for this work by sending them for a time to the battalions to see how regimental work is done.

7. To provide temporary assistance when needed to casualty clearing stations

belonging to the army of which the divisional field ambulances form part.

8. To establish advanced operating stations for immediate emergency operations, such as those required in cases of abdominal wounds.

9. To supplement the sanitary work of battalion medical officers when the battalions concerned are located in places which are out of the fighting line but not in direct charge of the sanitary staffs of the army of which the battalions form part.

10. To do for divisions and corps any work for which by the army, and which kind of scientific knowledge medical officers commonly possess. It may be said, in short , of the British armies in France the medical bonne a tout faire of the front.

No single field ambulance ever undertakes simultaneously all the duties mentioned, and the way in which they are allocated varies; for the environment of the divisions are not identical, and the senior medical officer of each of the armies and corps on the Western front (subject to orders from a higher authority) exercises his discretion as to the fashion in which he provides for the aggregate medical requirements of the troops in his charge. The experiences of field ambulance medical officers are therefore liable to differ, more especially if the period over which they are compared is relatively short. Commonly, whatever duties have to be performed are taken in turn by each field ambulance available, the period for which it remains employed thereon varying according to circumstances.

If a division is engaged in an active part of the line its evacuation work is usually sufficient to occupy the attention of all its field ambulances, and the same is true of those of a corps when this is taking part in an advance or definite battle. In such cases the other duties are assigned to the ambulances of reserve or other divisions.

In trench warfare each division engaged generally makes its own arrangements for evacuation, the ambulances belonging to it sometimes acting as independent units, sometimes pooling their resources.