1. The English word "kiss" comes from the Old English "cyssan", which in turn comes from "kuss" or "kussijanan". These are Proto-Germanic words that probably come from the sound made when two people kiss each other.

2. Philematology is a branch of science that studies kissing.

3. A normal kiss involves only two facial muscles, while the French - 34.

4. The circular muscle of the mouth is the main muscle that is involved in a kiss.

5. Lips top the list of the most sensitive parts of the body. Scientists say that the genitals are not as sensitive as the lips. In addition, the fingertips are 100 times less sensitive than the lips.

6. Male and female lips have a close resemblance to the labia.

7. A woman can achieve orgasm just by kissing a man, but this requires that he kisses perfectly.

8. Kissing helps to burn calories. Yes, you can really lose weight by kissing. One passionate kiss can burn up to 6.4 calories. This means that in four minutes of continuous kissing, you will burn 25.6 calories. That's how much you'll spend walking for five minutes at your usual pace.

9. Sucking and kissing are almost identical. According to some scientists, it is possible to determine whether a person was fed from a bottle or breast, by the way he or she kisses.

10. It is reported that people who kiss more often do not have problems with their teeth. This is due to an increase in salivation during a kiss. Saliva protects teeth and prevents the formation of plaque.

11. The human mouth is a hotbed of bacteria. During the kiss, bacteria are exchanged. Their number can vary from 10 million to 1 billion.

12. During the kiss, not only bacteria are transmitted, but also proteins, mineral salts and fats. Studies show that as a result of metabolism, the production of antibodies increases. These antibodies help fight not only antigens that are transmitted during a kiss, but also those that are present in the environment.

13. English is the source of the term "French kiss". It originated in 1923 as an affront to French culture, which at the time was considered overly concerned with sex.

14. French kiss in France is called "kiss of souls". The French believe that two souls merge together if the French kiss is done correctly.

15. Savolium (French kiss), Basium (kiss on the lips) and Osculum (kiss on the cheek) are three different types of kisses that were invented by the Romans.

16. The first written evidence of a kiss was found in four ancient Vedas of the Hindu religion. These texts were written 1500 years before the birth of Christ.

17. In one Japanese medieval manuscript there is a warning for men. The text asks men to avoid passionate kisses with a woman when she has an orgasm, as there is a high probability that she can bite off the tongue of her lover.

18. In the ancient Indian guide to sex "Kama Sutra" describes 30 different types of kisses. One of the types of kisses mentioned in it is known as the "struggle of tongues."

19. Studies show that almost 2/3 of people tilt their heads to the right during a kiss. According to scientists, this preference actually develops when the baby is still in the womb.

20. According to Pinly, a common cold can be cured by simply kissing the nostril of a donkey. In roman tradition, contracts were signed with kisses. This led to the emergence of a tradition according to which the wedding ceremony is completed with a kiss.