are available). The MSR Waterworks, First Need, and Basic Designs systems, though not as efficient or durable as the Katadyn, cost far less and are sensible alternatives. No simple filtration system, including those referenced, can render salty or otherwise mineralized water potable.

Fieldworkers should be aware that simply boiling water makes it relatively safe and potable, but only if it is kept at a full, rolling boil for at least 20 minutes. Limited fuel often makes this water-purification method impossible, especially at high altitudes. Boiling also does not remove the particulate matter, herbicides, pesticides, and some of the smaller microbial agents (such as Giardia and other protozoa and bacteria) as do the Katadyn, MSR Water works, and General Ecology Trav-LPure microfiltration systems.

Treatment of water with iodine or other chemicals is not recommended since these techniques are inefficient water purifiers and some individuals suffer nausea and stomach cramps as a side effect.

The quality and quantity of locally available foodstuffs vary greatly across China, but in general, acquiring fresh meats, vegetables, and fruits is more problematic in the north than in the south, regardless of season. Individual researchers should decide in advance the extent to which the demands of particular field activities will require them to bring quantities of packaged ''backpacking food" from the West. In such cases, primary considerations include whether or not base camps can be established near main transportation arteries, the number of people participating in the fieldwork, and cost, because such "convenience foods" are vastly more expensive than locally available supplies.

While small camp stoves that burn bottled butane are convenient, they should be avoided in China since they cannot be transported by air (intrepid but uninformed mountaineering expeditions regularly have their bottled fuel confiscated by Chinese airport authorities, much to their chagrin) and replacement canisters are not yet available in China.

The new multi-fuel stoves, such as MSR's International and X-GK II or Coleman's Peak 1, are good alternatives to those that burn butane. Multi-fuel stoves have the advantage of being able to burn nearly any combustible liquid, from leaded or unleaded gasoline and diesel fuel to kerosene. One field researcher working in Xinjiang reports he successfully ran an MSR X-GK II stove for an entire field season on low-octane gasoline siphoned from a jeep supplemented with aviation fuel purchased at a local airport! Such stoves are extremely compact, efficient, user-friendly, and relatively inexpensive (about $75).

For base camp applications (not including demanding high-altitude work), another option is to purchase a Chinese-made kerosene (paraffin) stove locally. A wide range of models is available, from Primus