1. Combine chocolate and water in top of a double boiler and set it over hot, not boiling, water until chocolate melts. Stir it occasionally. With wire wisk. Remove and set it aside to cool, stirring once in a while.

2. Beat the egg yolks in a large bowl. Beat in the sugar gradually.

3. Continue to beat until the mixture is pale yellow and the consistency of cream sauce. When the beater is lifted out, the mixture will fall in a ribbon.

4. Now add the cooled, melted chocolate and beat it in until it is well blended.

5. Put the egg whites into a second large bowl. With clean beaters, beat them at medium speed until they are foamy. Add salt, then beat until stiff peaks form.

6. To soften the chocolate mixture stir about a cup of the beaten egg whites into it. The rest of the egg whites is folded into the chocolate mixture. To fold: using a rubber spatula, cut down one side of the mixture, come across the bottom, up the other side, and across the top bringing some of the mixture up from the bottom. Give the bowl a quarter turn, repeat folding motion. Continue until chocolate and egg whites are combined.

7. The mousse is poured into a serving dish or bowl or it can be put into individual cups. Cover and chill several hours or overnight.