It is a fundamental dictum of Sushruta that in a case of medical treatment the then prevailing season of the year should be taken into account. In his Samhita we find two distinct classifications of seasons, one based on the peculiar physical phenomena which distinguish the different seasons of the year, a fact which emphatically proves that Sushruta was an inhabitant of the sub-Himalayan Gangetic Doab, the other is for the purpose of showing the respective accumulation, aggravation and subsidence of morbific diatheses (Doshas). In the same manner the different quarters of the day and night have been minutely charted or set down to show the spontaneous aggravation and subsidence of the deranged Vayu, Pittam and Kaphah during the 24 hours. The influence of planets as to the production of certain diseases such as small-pox, measles, scarlet fever, etc. is almost a proved fact. As it governs the prevalence and non-prevalence of certain maladies, the aggravation and non-aggravation of certain existing disorders as well owe much of their origin to this potent factor. The vegetable kingdom from which we glean our daily food is also subject to this influence, and hence the discrimination we exercise in selecting our food on certain days of the lunar month.
Countries have been divided into Jangala or A'nupa according as their physical features partake of the character of a dry plateau or of a swamp or marsh, a Sadharana one possessing features, which are common to both. Diseases, which are natural or are spontaneously relieved in each of these kinds of country have been treated with that scientific insight which marks modern medical works on sea-side or spring sanitariums. The virtues of the waters of different rivers of India were ascertained for the purposes of practical therapeutics. The therapeutic properties of the milk of a she-goat, she-buffalo, mare, cow-elephant, or woman, as well as of any of their modifications such as curd, whey etc. together with the properties of the flesh and urine of the several groups of she-animals, which are indigenous to the land, were studied and analysed, thus placing at the disposal of a practical physician a list of dietary in different diseases to soothe the taste of the most fastidious patient, and which is at the same time potent enough to cure the distemper he is suffering from without the help of any special medicine. Thus it is that we find our Vaidyas prescribing the flesh of many carnivorous animals as a diet in consumption, goat's meat in phthisis, goat's milk in colitis and Tittira's flesh in fever &c
In treating of the diseases of the kidneys, bladder and the urethra, Sushruta has described the symptoms and the colour of the urine in, each specific variety without laying down any mode of testing the urine. But we know that Sushruta has enjoined his readers at the very outset of his work to refer to other allied branches of the science for information which is not contained in his book. In the same manner we can account for the absence of any instructions as regards the feeling of the pulse as an important auxiliary in making a correct diagnosis. We need but repeat the statement that the readers of this Samhita must look for this information in the Kanada's Nadi Vijnanam, which has made our Vaidyas such expert sphygmologists.