If you wanna gain muscle, you need to focus on 3 things:
1. lift. of course, that's quite obvious. But doing a lot of reps using a low weight isn't useful at all. Do less reps & sets, using an higher weight. Do squats and deadlifts, they're probably the best exercises you can do to gain muscle :). Of course, they're not the only ones, but many people would rather avoid those, because they're "tough"... Do them! And prepare a good schedule! On the internet you can find a number of good schedules: you can use them, editing something if you want to.
2. eat. Eating is essential if you wanna gain muscle: eat 6 times a day, and eat well. Eat about 1 g of proteins for every pound you weight, and eat the exact amount of calories you need (google if you don't know that amount).
3. rest. Rest is very important, so got getting enough isn't good for your muscle. Sleep at least 8 hours a day, so that your muscle can grow better

no way you curl 140 lbs... People 200+ lbs can barely curl that, let alone for 50 reps. I have special knowledge on weight training and building muscle/strength in general. Give me more information like height, body type, meals, etc and i can help you pretty easily

Gaining weight in the form of muscle improves your appearance and strength. Your age, body type, genetics and gender affect the way you put on muscle. If you meticulously follow specific strategies, expect to put on as much as a 1/2 lb. of muscle per week.

Step 1
Lift heavy weights consistently. Perform a strength training routine that recruits all of the major muscles of the body at least two non-consecutive days per week. You simply cannot build muscle without weight training.


Step 2
Use free weights for the majority of your exercises. Execute moves like barbell squats, bent-over barbell rows, dumbbell triceps overhead extensions, barbell biceps curls, dumbbell chest presses and dumbbell lateral raises. Free weights recruit a greater number of moves with each repetition, resulting in faster muscle growth.

Step 3
Increase your daily calorie intake to support your strength training efforts. Go for about 250 to 500 calories more than you burn in a day, recommends Dr. Melina Jampolis, CNN’s physician nutrition specialist. Spread your calories out over the course of five to six meals during the day to provide your muscles with a constant influx of nutrients.

Step 4
Choose healthy foods. Avoid processed and fast foods that may contain a lot of calories, but are low in nutrition and high in saturated and trans fats, sodium and sugar--compounds that do not support muscle growth. Eat unsaturated fats and carbohydrates in the form of vegetables and whole grains to provide your body with energy and nutrition to help create muscle. Eat foods like nuts, chunky soups, protein smoothies and milk to pad your daily calorie intake.

Step 5
Strive to eat about 1g of protein per lb. of body weight daily. Obtain your protein from sources like egg whites, whey protein powder, cottage cheese, fish, white-meat poultry and lean beef.

Step 6
Consume protein around your workouts. Eat a snack or meal containing a complete amino acid profile—such as meat, soy or whey protein—as soon as possible post exercise as it stimulates a great increase in muscle protein synthesis, as affirmed by the International Society of Sports Nutrition. Add a carbohydrate to this snack to stimulate even greater muscle growth.

Tips and Warnings
If you are short on time or prefer to be in the gym more often, try splitting up your workout over several days. For example, do legs and shoulders on Monday, back and biceps on Wednesday and chest and triceps on Thursday. Rest through the weekend, or perform a full body workout on Saturday to hit every muscle group two times for the week. Good examples of post-exercise nutrition are smoothies made with whey or soy protein or a turkey sandwich.

Things You'll Need
Free weights
Proteins like chicken, whey powder and lean beef

References
1- IronMagazine.com: 10 Things You Must Do to Gain Muscle Mass

2- CNNHealth.com: How Should I Eat to Build Muscle Mass

3- American Council on Exercise: Free Weights vs. Strength-training Equipment

4- Muscle and Fitness: How Much Protein, Carbohydrates and Fat Do You Need?

5- Journal of the International Society of Sports Nutrition: Position on Nutrient Timing

I totally agree rest is very important, but I do believe, the more you eat, the fast you gain weight, don't just eat any food, eat foods which are rich in proteins and somehow has fats, that will do.

Keep lifting and increase weight every week. Instead of drinking just protein think about gettin a weight gainer like mass peak. You need to eat more calories than you burn everyday or else you will stay the same weight. Unlike asphalto said you need 1.5g to 2g of protein per lb of body weight everyday.

If you're asking for muscle...

and you claim to have curled 140 lbs for 10 reps...

then you're e-statting. Phaggot.

You can't curl 140 lbs with perfect form...

Unless you're doing some wacky variation of a reverse clean...

What do you squat,deadlift,and bench?