154                                The Refractive Dispersion of Ghee

                                                    TABLE V

                                          Neutralization of ghee

Sample

Refractive index n

n 4358—
n 5460

Acidity
(per cent.
oleic)

R. I. n D

R. M.
value

P. V.

n4358

n5460

1. Mixed ghee . .

1.47247

1.46375

.00872

4.5

1.4540

24.0

0.86

2. „ neutralized .

1.47287

1.46434

.00853

. .

1.4546

. .

. .

3. Buffalo ghee
(Murrah)

1.47130

1.46266

.00864

2.6

1.4530

1.3

4. „ neutralized

1.47181

1.46325

.00856

1.4534

. .

. .

5. Sindhi cow ghee .

1.47256

1.46385

.00871

1.1

1.4542

26.7

1.7

6. „ neutralized .

1.47235

1.46385

.00850

. .

1.4543

. .

. .

7. Ayrshire cow ghee .

1.47221

1.46365

.00856

1.4

1.4539

26.9

0.6

8. „ neutralized .

1.47205

1.46348

.00850

. .

1.4543

..

. .

The dispersion is lowered still further so that no useful purpose is served by neutralizing ghee
to study its purity.

The main part of the study was to find out if this constant could be used to detect adulteration.
Four oils were used as seen from Table VI.

                                                      TABLE VI

                                              Adulterants of ghee

Sample

Scale reading

Refractive index

n4358—
n5460

R.I.
n D

4358

5460

n4358

n5460

1. Groundnut oil . . . . . . .

44° 57.5'

43° 10'

1.48098

1.47178

.00920

1.4625

2. Coconut oil . . . . . . . . . . ..

47° 30.0'

45° 30'

1.46596

1.45788

.00808

1.4489

3. Hardened groundnut oil I . . . . .

45° 19.7'

43° 29'

1.47881

1.46990

.00891

1.4601

4. „ „ II . . .

45° 35.8'

43° 44'

1.47721

1.46841

.00880

1.4593

The two hardened oils have much the same dispersion as ghee : mixtures of these with ghee were
accordingly studied (Table VII).

                                                    TABLE VII

                    Artificial adulteration with hydrogenated groundnut oil

Sample

Main scale reading

Refractive index

n 4358—
n 5460

R.I.

4358

5460

n 4358

n5460

1. Hydrogenated oil I

45° 19.7'

43° 29'

1.47881

1.46990

.00891

1.4601

2. 5 per cent + good old ghee

46° 30.5'

44° 35'

1.47182

1.46335

.00847

1.4540

3. 10 per cent + good old ghee

46° 24.7'

44° 30'

1.47241

1.46385

.00856

1.4541

4. 15 per cent + good old ghee

46° 19.6'

44° 26'

1.47291

1.46425

.00866

1.4545

5. 20 per cent + good old ghee

46° 18.4'

44° 24'

1.47312

1.46444

.00868

1.4550

6. Hydrogenated oil II

45° 35.8'

43° 44'

1.47721

1.46841

.00880

1.4593

7. 5 per cent + good old ghee

46° 33.1'

44° 38'

1.47156

1.46305

.00851

1.4538

8. 10 per cent+good old ghee

46° 26.8'

44° 32'

1.47219

1.46365

.00854

1.4540

9. 15 per cent+good old ghee

46° 25.3'

44° 31'

1.47234

1.46375

.00859

1.4544

10. 20 per cent+good old ghee

46° 21.2'

44° 28'

1.47275

1.46405

.00870

1.4546

11. Sample of ghee used in above
adulteration

46° 35.8'

44° 42'

1.47130

1.46266

.00864

1.4530