There exists at present a good deal of misconception with regard to the practices of Hatha Yoga. People easily believe in the stories told by those who themselves hear them second-hand, and no attempt is made to find out the truth by a direct reference to some good treatise. It is generally believed that the six practices, (Satkarma) in Hatha Yoga are compulsory for the student and that besides being dirty, they are fraught with danger to the practitioner. This is not true, for these practices are necessary on in case there exist inpurities in the Nadis, and not otherwise. There are two classes of students of Yoga (1) those who study it theoretically; (2) those who combine the theory with practice. Yoga is of very little use, if studied theoretically. It was never meant for such a study. In its practical form. However, the path of the student is beset with difficulties. The books on Yoga give instructions so far as it is possible to express the methods in word.