Borax is not used:

Options

A. as a styptic to stop bleeding
B. in making enamel and pottery glazes
C. as a flux in soldering
D. in making optical glasses.

Explanation

To determine which option does not represent a use of borax, we will analyze each option step by step.

### Step 1: Understand what Borax is
Borax is a compound with the chemical formula Na2B4O7·10H2O. It is commonly used in various applications due to its properties.

**Hint:** Recall the chemical formula and basic properties of borax.

### Step 2: Analyze Option 1 - As a septic to stop bleeding
Option 1 states that borax is used as a septic to stop bleeding. While borax can have antiseptic properties, it is not effective as a blood coagulant, which is necessary to stop bleeding.

**Hint:** Differentiate between antiseptic and blood coagulant functions.

### Step 3: Analyze Option 2 - In making enamel and pottery glazes
Option 2 mentions that borax is used in making enamel and pottery glazes. This is true; borax is indeed used in the manufacturing of these materials, providing a shiny finish.

**Hint:** Think about the applications of borax in ceramics and glazes.

### Step 4: Analyze Option 3 - As a flux in soldering
Option 3 states that borax is used as a flux in soldering. This is also correct; borax is commonly used in metallurgical processes to help join metals together.

**Hint:** Remember the role of flux in soldering and metal joining.

### Step 5: Analyze Option 4 - In making optical glasses
Option 4 claims that borax is used in making optical glasses. This is accurate as well; borax is used in the production of heat-resistant boron silicate glasses.

**Hint:** Consider the properties of boron silicate glasses and their applications.

### Conclusion
After analyzing all options, we find that:
- Option 1 (as a septic to stop bleeding) is **not** a use of borax.
- Options 2, 3, and 4 are valid uses of borax.

Thus, the correct answer is **Option 1**.