This section is from the book "The Practice Of Palmistry For Professional Purposes", by C. de Saint-Germain. Also available from Amazon: The Practice of Palmistry for Professional Purposes.
It has often been said by scientists of recognized capacity, that the nails are nothing but the electric fluid within us solidified by exposure to the air, thus becoming a kind of intermediary substance between the said fluid and the human skin and flesh. Balzac wrote in Louis Lambert:
"When one thinks that the line separating our flesh from the growl contains the unexplained and invisible mystery of the incessant transformation of our fluid into horn, one must admit that nothing is impossible in the marvelous transformation of the human constituting- elements."
Short nails - Inquisitivcness, intuition, energy. In a weak hand: frivolous dis-position, Short, hard, and partially covered with skin, and even flesh- - Quarrelsome disposition, especially if they are broader than long. Seen at its worst on what I call a clubbed thumb. (See chapter on Thumb. A German scientist observed that after a violent access of rage the nails of the subject under examination would become softer for a while.)
Short nails with a soft palm - The born critic's attribute; irony and even scorn.
A short nail on the second finger, the nails of the other fingers being almondshaped - Irritability, but only at times; always extreme sensitiveness to criticism.
Short and pale - Deceitful disposition; physical and moral weakness.
Short and red - Violent temper.
Short, square-shaped and bluish - Heart trouble.
Short, quite broad and square at the bottom - Passionate anger. If wider than long - Unsufferable stubbornness.
Short and triangular shaped: The point of the triangle nearest to the phalanx - Threatened paralysis.
Short, narrow and curved - Danger of spina! troubles.
Large (both broad and long) and rounded at the base - Gear, sound judgment.
Long nails, especially if thin and brit-tle - Weak physical nature, often lack of intelligence.
Long, thin and curved - Sore throat and weak respiratory organs. If ridged or fluted - A sure sign of consumption.
Long, thick and curved, somewhat like a claw - Violent disposition in love and other intercourse with one's fellow-beings, Long, thin, narrow - Timidity and cowardice; often found in convalescing persons.
Moderately thin and narrow - Excellent general disposition.
Perfect nails, white, almond-shaped and naturally polished, moderately long and thick - Happy nature, Satisfactory state of health; strange to say. it has been observed that perfect almond-shaped nails are frequency found OH the fingers of conceited and selfish subjects, especially women.
If pink on the outer edge - Short fits of anger, never malicious.
Ridges on the nail of a certain finger - Held by Desbarrolles to indicate a stronger devotion and aptitude of the subject to the particular art or profession which that finger represents more specially.
Cross ridges - Dr. Bain, a famous physician, states that in his experience the presence of a deep cross ridge on a nail announces a coming disease which will manifest itself by other symptoms before the nail has grown so that the ridge gets to the edge of the nail. The nature of the disease can be judged by the finger upon which this nail is found. The thumb nail is particularly interesting in this connection. As it takes six months for a nail to be entirely renewed it is easy to estimate in bow long a time the illness will be due.
Not only the modern physician, but the most ancient in the art, believed that the shape, color, etc., of the nails denoted certain diseases. Hippocrates (460-357 B. C.) wrote that the Nail of the first finger much bent inward indicates scrofula and consumption; and to this day this diagnosis is accepted as correct.
I decline introducing into this work - which is essentially a practical, and, as far as possible, reliable Guide to Hand-reading, the unsubstantiated indications furnished by the white or dark spots on the nails and by the examination of the moons at the lower part of the nails. A branch of Chiromancy known by the name of Onychomancy (divination by the nails) obtained some success in the XVII. Century, but it never reached that point when it could be admitted on a par with the more ancient and more satisfactorily verified Palmistry, and I prefer leaving it out of my present treatise. I may state, however, that Medical men have often admitted in my presence, that Numerous white spots on the nails indicate poverty of the blood and defective circulation, while Black or bluish spot's on the nails frequently accompany poisoning of the blood, especially in cases of cholera or yellow fever, and even typhoid fever, diphtheria and small-pox.